#-swank
(unless (member :child-sbcl *features*)
  "I refered from https://competitive12.blogspot.com/2020/03/common-lisp.html thank you!"
  (quit
   :unix-status
   (process-exit-code
    (run-program *runtime-pathname*
                 `("--control-stack-size" "128MB"
                   "--noinform" "--disable-ldb" "--lose-on-corruption" "--end-runtime-options"
                   "--eval" "(push :child-sbcl *features*)"
                   "--script" ,(namestring *load-pathname*))
                 :output t :error t :input t))))
#-swank
(unless (member :child-sbcl *features*)
  "I refered from https://competitive12.blogspot.com/2020/03/common-lisp.html thank you!"
  (quit
   :unix-status
   (process-exit-code
    (run-program *runtime-pathname*
                 `("--control-stack-size" "256MB"
                   "--noinform" "--disable-ldb" "--lose-on-corruption" "--end-runtime-options"
                   "--eval" "(push :child-sbcl *features*)"
                   "--script" ,(namestring *load-pathname*))
                 :output t :error t :input t))))
(defmacro dpline (name args memo-size &body body)
  (let ((memo (gensym)))
    `(let ((,memo (make-array ,memo-size :initial-element nil)))
       (defun ,name ,args
         (or (aref ,memo ,@args)
             (setf (aref ,memo ,@args)
                   ,@body))))))

(defmacro dphash (name args &body expr)
  `(let ((table (make-hash-table :test #'equal)))
     (defun  ,name ,args
       (or (gethash (list ,@args) table)
           (setf (gethash (list ,@args) table)
                 (progn
                   ,@expr))))))

(defun split (x str)
  (let ((pos (search x str))
        (size (length x)))
    (if pos
        (cons (subseq str 0 pos)
              (split x (subseq str (+ pos size))))
        (list str))))

(defmacro collect-times (time body)
  `(loop repeat ,time collect ,body))

(defun read-times (time)
  (collect-times time (read)))

(defmacro aif (expr then else)
  `(let ((it ,expr))
     (if it ,then ,else)))

(defmacro awhen (expr &rest then)
  `(aif ,expr (progn ,@then) nil))

(defun comulative (function list &key base)
  (if base
      (comulative function (cons base list))
      (do ((lst (cdr list) (cdr lst))
           (acc (list (car list))))
          ((null lst) (reverse acc))
        (push (funcall function (car acc) (car lst)) acc))))

(defun binary-search (function left right
                      &optional
                        (eps 1)
                        (average-function (lambda (x y) (ash (+ x y) -1))))
  (if (<= (abs (- left right)) eps)
      right
      (let ((mid (funcall average-function left right)))
        (if (funcall function mid)
            (binary-search function left mid eps average-function)
            (binary-search function mid right eps average-function)))))

(defun arithmetic-mean (&rest body)
  (/ (apply #'+ body) (length body)))

(defvar +MOD+ (+ (expt 10 9) 7))

(defun range-0-n (n &optional (step 1))
  (loop for i from 0 below n by step collect i))

(defun range-1-n (n &optional (step 1))
  (loop for i from 1 below n by step collect i))

(defun range-a-b (a b &optional (step 1))
  (loop for i from a below b by step collect i))

(defun map-0-n (function n &optional (step 1))
  (mapcar function (range-0-n n step)))

(defun map-1-n (function n &optional (step 1))
  (mapcar function (range-1-n n step)))

(defun map-a-b (function a b &optional (step 1))
  (mapcar function (range-a-b a b step)))

(defun read-string (&optional (stream *standard-input*))
  (labels ((is-empty (x)
             (or (char= x #\space) (char= x #\newline))))
    (loop for char = (read-char stream)
          with result
          when (and result (is-empty char))
            do (return (concatenate 'string (nreverse result)))
          when (null (is-empty char))
            do (push char result))))

(defun merge-sort (lst &optional (compare #'<))
  (let ((turn 0))
    (labels ((merge-list (a b a-length b-length)
               (cond ((zerop a-length) b)
                     ((zerop b-length) a)
                     ((funcall compare (car b) (car a))
                      (incf turn a-length)
                      (cons (car b)
                            (merge-list a (cdr b) a-length (1- b-length))))
                     (t
                      (cons (car a)
                            (merge-list (cdr a) b (1- a-length) b-length)))))
             (f (lst length)
               (if (= length 1)
                   lst
                   (let ((mid (ash length -1)))
                     (merge-list (f (subseq lst 0 mid) mid)
                                 (f (subseq lst mid) (- length mid))
                                 mid
                                 (- length mid))))))
      (values (f lst (length lst)) turn))))

(defun group (lst &optional (test #'eql) (key nil))
  (let ((table (make-hash-table :test test)))
    (mapc (lambda (x)
            (push x (gethash (if key (funcall key x) x) table)))
          lst)
    (loop for value being each hash-value in table
          collect value)))

(defun nearby (&rest args)
  (let ((current (subseq args 0 (ash (length args) -1)))
        (validator (subseq args (ash (length args) -1)))
        (res nil))
    (labels ((check ()
               (every (lambda (x y) (and (<= 0 x) (< x y)))
                      current validator))
             (f (lst)
               (unless lst (return-from f))
               (let ((x (car lst)))
                 (setf (car lst) (1+ x))
                 (when (check) (push (copy-list current) res))
                 (setf (car lst) (1- x))
                 (when (check) (push (copy-list current) res))
                 (setf (car lst) x))
               (f (cdr lst))))
      (f current)
      res)))

(defun log2-int (str)
  (loop for i across str
        with res = 0
        do
           (progn
             (setf res (ash res 1))
             (incf res (- (char-code i) (char-code #\0))))
        finally (return res)))

(defun pop-count (x)
  (labels ((f (x)
             (if (zerop x)
                 0
                 (+ (if (oddp x) 1 0)
                    (f (ash x -1))))))
    (f x)))

(defun func (x)
  (labels ((f (x)
             (if (zerop x) 0
                 (1+ (f (mod x (pop-count x)))))))
    (f x)))

(defun main (n str)
  (let* ((pop-num (count #\1 str))
         (num (log2-int str))
         (divide-by-up (mod num (1+ pop-num)))
         (divide-by-down (if (>= pop-num 2)
                             (mod num (1- pop-num))
                             num)))
    (reverse
     (loop for char across (reverse str)
           for i below n
           with pows-up = 1
           with pows-down = (if (= pop-num 2) 0 1)
           when (char= char #\0)
             collect
             (1+ (func (mod (+ divide-by-up pows-up)
                            (1+ pop-num))))
           when (char= char #\1)
             collect
             (if (= pop-num 1)
                 0
                 (1+ (func (mod (- divide-by-down pows-down)
                                (1- pop-num)))))
           do
              (progn
                (setf pows-up (mod (ash pows-up 1) (1+ pop-num)))
                (when (>= pop-num 2)
                  (setf pows-down (mod (ash pows-down 1) (1- pop-num)))))))))

(format
 t
 "~{~a~%~}"
 (main (read) (read-line)))


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  "NOTE: cannot read -2^62"
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setq minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10))
                                         result))))
              (return (if minus (- result) result))))))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun main ()
  (let* ((n (read))
         (as (make-array n :element-type 'uint31 :initial-element 0)))
    (dotimes (i n)
      (setf (aref as i) (read-fixnum)))
    (setq as (sort as #'>))
    (let ((pos 0)
          (rest (- n 1))
          (res 0))
      (loop while (> rest 0)
            do (cond ((= pos 0)
                      (incf res (aref as 0))
                      (decf rest))
                     ((= rest 1)
                      (incf res (aref as pos))
                      (decf rest))
                     (t (incf res (* 2 (aref as pos)))
                        (decf rest 2)))
               (incf pos))
      (println res))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)
    #+os-unix (run-program "xsel" () :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "4
2 2 1 3
"
    "7
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "7
1 1 1 1 1 1 1
"
    "6
")))

Global OOD problem IDs are disjoint from train, validation, and in-distribution test problem IDs.

Score: 400 points

Problem Statement

Quickly after finishing the tutorial of the online game ATChat, you have decided to visit a particular place with N-1 players who happen to be there. These N players, including you, are numbered 1 through N, and the friendliness of Player i is A_i.

The N players will arrive at the place one by one in some order. To make sure nobody gets lost, you have set the following rule: players who have already arrived there should form a circle, and a player who has just arrived there should cut into the circle somewhere.

When each player, except the first one to arrive, arrives at the place, the player gets comfort equal to the smaller of the friendliness of the clockwise adjacent player and that of the counter-clockwise adjacent player. The first player to arrive there gets the comfort of 0.

What is the maximum total comfort the N players can get by optimally choosing the order of arrivals and the positions in the circle to cut into?

Constraints

All values in input are integers.

2 \leq N \leq 2 \times 10^5

1 \leq A_i \leq 10^9

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 \dots A_N

Output

Print the maximum total comfort the N players can get.

Sample Input 1

4
2 2 1 3

Sample Output 1

7

By arriving at the place in the order Player 4, 2, 1, 3, and cutting into the circle as shown in the figure, they can get the total comfort of 7.

They cannot get the total comfort greater than 7, so the answer is 7.

Sample Input 2

7
1 1 1 1 1 1 1

Sample Output 2

6

Submitted source-code file size, in bytes.

Execution CPU time reported by official Project CodeNet metadata, in milliseconds.

Peak memory usage reported by official Project CodeNet metadata, in kilobytes.


(let* ((n (read))
       (a (make-array `(,n) :initial-element 0))
       (ans 0))
  (loop :for i :from 1 :to n
        :do (setf (aref a (1- i)) (read)))
  ;;
  (setf a (sort a #'>))
  ;;
  (incf ans (aref a 0))
  ;;
  (loop :for i :from 1 :to (floor (/ (- n 2) 2))
        :do (incf ans (* 2 (aref a i))))
  (when (oddp (- n 2))
    (incf ans (aref a (ceiling (/ (- n 2) 2)))))
  (format t "~A~%" ans))


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
;;;
;;; Arithmetic operations with static modulus
;;;

;; FIXME: Currently MOD* and MOD+ doesn't apply MOD when the number of
;; parameters is one.
(defmacro define-mod-operations (divisor)
  `(progn
     (defun mod* (&rest args)
       (reduce (lambda (x y) (mod (* x y) ,divisor)) args))

     (defun mod+ (&rest args)
       (reduce (lambda (x y) (mod (+ x y) ,divisor)) args))

     #+sbcl
     (eval-when (:compile-toplevel :load-toplevel :execute)
       (locally (declare (muffle-conditions warning))
         (sb-c:define-source-transform mod* (&rest args)
           (if (null args)
               1
               (reduce (lambda (x y) `(mod (* ,x ,y) ,',divisor)) args)))
         (sb-c:define-source-transform mod+ (&rest args)
           (if (null args)
               0
               (reduce (lambda (x y) `(mod (+ ,x ,y) ,',divisor)) args)))))

     (define-modify-macro incfmod (delta)
       (lambda (x y) (mod (+ x y) ,divisor)))

     (define-modify-macro decfmod (delta)
       (lambda (x y) (mod (- x y) ,divisor)))

     (define-modify-macro mulfmod (multiplier)
       (lambda (x y) (mod (* x y) ,divisor)))))

(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  "NOTE: cannot read -2^62"
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setq minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10))
                                         result))))
              (return (if minus (- result) result))))))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(define-mod-operations +mod+)

(defun solve (as k)
  (declare ((simple-array int32 (*)) as))
  (let* ((n (length as))
         (n+ 0)
         (n- 0)
         (as+ (make-array n :element-type 'uint31 :initial-element 0))
         (as- (make-array n :element-type 'uint31 :initial-element 0)))
    (dotimes (i n)
      (let ((a (aref as i)))
        (cond ((> a 0)
               (setf (aref as+ n+) a)
               (incf n+))
              ((< a 0)
               (setf (aref as- n-) (- a))
               (incf n-)))))
    (setq as+ (sort as+ #'>)
          as- (sort as- #'>))
    (dbg as+ as-)
    (let ((cumuls+ (make-array (+ n+ 1) :element-type 'uint31 :initial-element 1))
          (cumuls- (make-array (+ n- 1) :element-type 'uint31 :initial-element 1))
          (logcumuls+ (make-array (+ n+ 1) :element-type 'double-float :initial-element 0d0))
          (logcumuls- (make-array (+ n- 1) :element-type 'double-float :initial-element 0d0))
          (as (delete 0 as)))
      (dotimes (i n+)
        (let ((a (aref as+ i)))
          (setf (aref cumuls+ (+ i 1)) (mod* (aref cumuls+ i) a)
                (aref logcumuls+ (+ i 1)) (+ (aref logcumuls+ i) (log (float a 1d0) 1.1d0)))))
      (dotimes (i n-)
        (let ((a (aref as- i)))
          (setf (aref cumuls- (+ i 1)) (mod* (aref cumuls- i) a)
                (aref logcumuls- (+ i 1)) (+ (aref logcumuls- i) (log (float a 1d0) 1.1d0)))))
      (setq as (sort as #'> :key #'abs))
      ;; (let ((res 0)
      ;;       (maxlog most-negative-double-float))
      ;;   (loop for d- from 0 to k by 2
      ;;         for d+ = (- k d-)
      ;;         when (and (<= d- n-) (<= d+ n+))
      ;;         do (let ((log (+ (aref logcumuls+ d+) (aref logcumuls- d-))))
      ;;              (when (> (- log 1d-10) maxlog)
      ;;                (setq maxlog log
      ;;                      res (mod* (aref cumuls+ d+) (aref cumuls- d-)))))))
      (let ((minus 0)
            (res 1))
        #>as
        (dotimes (i (length as))
          (let ((a (aref as i)))
            (if (> a 0)
                (mulfmod res a)
                (if (= i (- k 1))
                    (if (evenp minus)
                        (let ((new-pos (position-if #'plusp as :start i)))
                          (mulfmod res (aref as new-pos)))
                        (mulfmod res a))
                    (progn
                      (mulfmod res a)
                      (incf minus))))
            (when (= i (- k 1))
              (return))))
        res))))

(defun main ()
  (let* ((n (read))
         (k (read))
         (as (make-array n :element-type 'int32 :initial-element 0)))
    (dotimes (i n)
      (setf (aref as i) (read-fixnum)))
    (let ((num+ (count-if #'plusp as))
          (num0 (count 0 as))
          (num- (count-if #'minusp as)))
      (dbg num+ num0 num-)
      (println
       (if (loop for d- from 0 to k by 2
                 for d+ = (- k d-)
                 thereis (and (<= d- num-) (<= d+ num+)))
           (solve as k)
           (let ((as (sort as #'< :key #'abs)))
             (reduce #'mod* as :end k :initial-value 1)))))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)
    #+os-unix (run-program "xsel" () :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "4 2
1 2 -3 -4
"
    "12
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "4 3
-1 -2 -3 -4
"
    "1000000001
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2 1
-1 1000000000
"
    "1000000000
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "10 10
1000000000 100000000 10000000 1000000 100000 10000 1000 100 10 1
"
    "999983200
")))

Score : 500 points

Problem Statement

Given are N integers A_1,\ldots,A_N.

We will choose exactly K of these elements. Find the maximum possible product of the chosen elements.

Then, print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).

Constraints

1 \leq K \leq N \leq 2\times 10^5

|A_i| \leq 10^9

Input

Input is given from Standard Input in the following format:

N K
A_1 \ldots A_N

Output

Print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).

Sample Input 1

4 2
1 2 -3 -4

Sample Output 1

12

The possible products of the two chosen elements are 2, -3, -4, -6, -8, and 12, so the maximum product is 12.

Sample Input 2

4 3
-1 -2 -3 -4

Sample Output 2

1000000001

The possible products of the three chosen elements are -24, -12, -8, and -6, so the maximum product is -6.

We print this value modulo (10^9+7), that is, 1000000001.

Sample Input 3

2 1
-1 1000000000

Sample Output 3

1000000000

The possible products of the one chosen element are -1 and 1000000000, so the maximum product is 1000000000.

Sample Input 4

10 10
1000000000 100000000 10000000 1000000 100000 10000 1000 100 10 1

Sample Output 4

999983200

Be sure to print the product modulo (10^9+7).


(defun main ()
  (let* ((n (read))
         (k (read))
         (a (make-array (list n)))
         (mx 0)
         (my 0)
         (s 0)
         (z 0)
         (x 1)
         (pe nil)
         (y 1)
         (_ (+ (expt 10 9) 7)))
    ;
    (loop :for i :from 0 :to n
          :do (let ((w (read)))
                (setf (aref a i) w)
                (if (= w 0) (incf z))))
    ;
    (when (> k (- n z))
      (format t "0~%")
      (return-from main))

    (setf a (sort a (lambda (a b) (> (abs a) (abs b)))))
    (loop :with i := 0
          :with j := 0
          :while (< j k)
          :if (/= (aref a i) 0)
          :do (progn
                (when (< (aref a i) 0)
                  (incf mx))
                (setf x (mod (* x (abs (aref a i))) _))
                (incf j))
          :do (incf i))
    (loop :with i := 0
          :with j := 0
          :while (< j k)
          :if (/= (aref a (- (1- n) i)) 0)
          :do (progn
                (when (< (aref a (- (1- n) i)) 0)
                  (incf my))
                (setf y (mod (* y (abs (aref a (- (1- n) i)))) _))
                (setf s i)
                (incf j))
          :do (incf i))

    (loop :named foo
          :for i :from (1+ s) :to (1- n)
          :if (> (aref a i) 0)
          :do (progn
                (setf pe (aref a i))
                (return-from foo)))

    (cond ((evenp mx)
           (format t "~A~%" x))
          (pe
           (let ((mm))
             (loop :named foo
                   :for i :from s :downto 0
                   :if (< (aref a i) 0)
                   :do (progn
                         (setf mm (aref a i))
                         (return-from foo)))
             (setf mm (mod (expt mm (- _ 2)) _))
             (format t "~A~%" (mod (* (mod (* x pe) _) mm) _))))
          (t
           (format t "~A~%" y)))))
(main)


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  "NOTE: cannot read -2^62"
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setq minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10))
                                         result))))
              (return (if minus (- result) result))))))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun main ()
  (let* ((n (read))
         (res (floor (* n (+ n 1) (+ n 2)) 6)))
    #>res
    #>n
    (dotimes (i (- n 1))
      (let ((u (read-fixnum))
            (v (read-fixnum)))
        (when (> u v)
          (rotatef u v))
        (decf res (* u (+ 1 (- n v))))))
    (println res)))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)
    #+os-unix (run-program "xsel" '("-b" "-o") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3
1 3
2 3
"
    "7
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
1 2
"
    "3
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "10
5 3
5 7
8 9
1 9
9 10
8 4
7 4
6 10
7 2
"
    "113
")))

Score : 600 points

Problem Statement

We have a tree with N vertices and N-1 edges, respectively numbered 1, 2,\cdots, N and 1, 2, \cdots, N-1. Edge i connects Vertex u_i and v_i.

For integers L, R (1 \leq L \leq R \leq N), let us define a function f(L, R) as follows:

Let S be the set of the vertices numbered L through R. f(L, R) represents the number of connected components in the subgraph formed only from the vertex set S and the edges whose endpoints both belong to S.

Compute \sum_{L=1}^{N} \sum_{R=L}^{N} f(L, R).

Constraints

1 \leq N \leq 2 \times 10^5

1 \leq u_i, v_i \leq N

The given graph is a tree.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
u_1 v_1
u_2 v_2
:
u_{N-1} v_{N-1}

Output

Print \sum_{L=1}^{N} \sum_{R=L}^{N} f(L, R).

Sample Input 1

3
1 3
2 3

Sample Output 1

7

We have six possible pairs (L, R) as follows:

For L = 1, R = 1, S = \{1\} and we have 1 connected component.

For L = 1, R = 2, S = \{1, 2\} and we have 2 connected components.

For L = 1, R = 3, S = \{1, 2, 3\} and we have 1 connected component, since S contains both endpoints of each of the edges 1, 2.

For L = 2, R = 2, S = \{2\} and we have 1 connected component.

For L = 2, R = 3, S = \{2, 3\} and we have 1 connected component, since S contains both endpoints of Edge 2.

For L = 3, R = 3, S = \{3\} and we have 1 connected component.

The sum of these is 7.

Sample Input 2

2
1 2

Sample Output 2

3

Sample Input 3

10
5 3
5 7
8 9
1 9
9 10
8 4
7 4
6 10
7 2

Sample Output 3

113


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  "NOTE: cannot read -2^62"
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setq minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48)
                              (* 10 (the (integer 0 #.(floor most-positive-fixnum 10))
                                         result))))
              (return (if minus (- result) result))))))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun main ()
  (let* ((d (read))
         (cs (make-array 26 :element-type 'uint8 :initial-element 0))
         (ss (make-array (list d 26) :element-type 'uint32 :initial-element 0))
         (prevs (make-array 26 :element-type 'int32 :initial-element -1)))
    (dotimes (i 26)
      (setf (aref cs i) (read-fixnum)))
    (dotimes (i d)
      (dotimes (j 26)
        (setf (aref ss i j) (read-fixnum))))
    (let ((res 0))
      (dotimes (i d)
        (let ((type (- (read-fixnum) 1)))
          (incf res (aref ss i type))
          (setf (aref prevs type) i)
          (dotimes (j 26)
            (decf res (* (aref cs j) (- i (aref prevs j)))))
          (println res))))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "5
86 90 69 51 2 96 71 47 88 34 45 46 89 34 31 38 97 84 41 80 14 4 50 83 7 82
19771 12979 18912 10432 10544 12928 13403 3047 10527 9740 8100 92 2856 14730 1396 15905 6534 4650 11469 3628 8433 2994 10899 16396 18355 11424
6674 17707 13855 16407 12232 2886 11908 1705 5000 1537 10440 10711 4917 10770 17272 15364 19277 18094 3929 3705 7169 6159 18683 15410 9092 4570
6878 4239 19925 1799 375 9563 3445 5658 19857 11401 6997 6498 19933 3848 2426 2146 19745 16880 17773 18359 3921 14172 16730 11157 5439 256
8633 15862 15303 10749 18499 7792 10317 5901 9395 11433 3514 3959 5202 19850 19469 9790 5653 784 18500 10552 17975 16615 7852 197 8471 7452
19855 17918 7990 10572 4333 438 9140 9104 12622 4985 12319 4028 19922 12132 16259 17476 2976 547 19195 19830 16285 4806 4471 9457 2864 2192
1
17
13
14
13
"
    "18398
35037
51140
65837
79325
")))

(Please read problem A first. The maximum score you can get by solving this problem B is 1, which will have almost no effect on your ranking.)

Beginner's Guide

Let's first write a program to calculate the score from a pair of input and output. You can know the total score by submitting your solution, or an official program to calculate a score is often provided for local evaluation as in this contest. Nevertheless, writing a score calculator by yourself is still useful to check your understanding of the problem specification. Moreover, the source code of the score calculator can often be reused for solving the problem or debugging your solution. So it is worthwhile to write a score calculator unless it is very complicated.

Problem Statement

You will be given a contest schedule for D days.
For each d=1,2,\ldots,D, calculate the satisfaction at the end of day d.

Input

Input is given from Standard Input in the form of the input of Problem A followed by the output of Problem A.

D
c_1 c_2 \cdots c_{26}
s_{1,1} s_{1,2} \cdots s_{1,26}
\vdots
s_{D,1} s_{D,2} \cdots s_{D,26}
t_1
t_2
\vdots
t_D

The constraints and generation methods for the input part are the same as those for Problem A.

For each d, t_d is an integer satisfying 1\leq t_d \leq 26, and your program is expected to work correctly for any value that meets the constraints.

Output

Let v_d be the satisfaction at the end of day d.
Print D integers v_d to Standard Output in the following format:

v_1
v_2
\vdots
v_D

Sample Input 1

5
86 90 69 51 2 96 71 47 88 34 45 46 89 34 31 38 97 84 41 80 14 4 50 83 7 82
19771 12979 18912 10432 10544 12928 13403 3047 10527 9740 8100 92 2856 14730 1396 15905 6534 4650 11469 3628 8433 2994 10899 16396 18355 11424
6674 17707 13855 16407 12232 2886 11908 1705 5000 1537 10440 10711 4917 10770 17272 15364 19277 18094 3929 3705 7169 6159 18683 15410 9092 4570
6878 4239 19925 1799 375 9563 3445 5658 19857 11401 6997 6498 19933 3848 2426 2146 19745 16880 17773 18359 3921 14172 16730 11157 5439 256
8633 15862 15303 10749 18499 7792 10317 5901 9395 11433 3514 3959 5202 19850 19469 9790 5653 784 18500 10552 17975 16615 7852 197 8471 7452
19855 17918 7990 10572 4333 438 9140 9104 12622 4985 12319 4028 19922 12132 16259 17476 2976 547 19195 19830 16285 4806 4471 9457 2864 2192
1
17
13
14
13

Sample Output 1

18398
35037
51140
65837
79325

Note that this example is a small one for checking the problem specification. It does not satisfy the constraint D=365 and is never actually given as a test case.

Next Step

We can build a solution (schedule) for this problem in the order of day 1, day 2, and so on. And for every partial solution we have built, we can calculate the goodness (satisfaction) by using the above score calculator. So we can construct the following algorithm: for each d=1,2,\ldots,D, we select the contest type that maximizes the satisfaction at the end of day d. You may have already encountered this kind of "greedy algorithms" in algorithm contests such as ABC. Greedy algorithms can guarantee the optimality for several problems, but unfortunately, it doesn't ensure optimality for this problem. However, even if it does not ensure optimality, we can still obtain a reasonable solution in many cases. Let's go back to Problem A and implement the greedy algorithm by utilizing the score calculator you just implemented!

Greedy methods can be applied to a variety of problems, are easy to implement, and often run relatively fast compared to other methods. Greedy is often the most powerful method when we need to process huge inputs.
We can further improve the score by changing the greedy selection criteria (evaluation function), keeping multiple candidates instead of focusing on one best partial solution (beam search), or using the output of greedy algorithms as an initial solution of other methods.
For more information, please refer to the editorial that will be published after the contest.


(defun solve (x)
  (+ (+ (* x x) (* (* x x) x)) x)
  )

(princ (solve (read)))

Score : 100 points

Problem Statement

Given an integer a as input, print the value a + a^2 + a^3.

Constraints

1 \leq a \leq 10

a is an integer.

Input

Input is given from Standard Input in the following format:

a

Output

Print the value a + a^2 + a^3 as an integer.

Sample Input 1

2

Sample Output 1

14

When a = 2, we have a + a^2 + a^3 = 2 + 2^2 + 2^3 = 2 + 4 + 8 = 14.

Print the answer as an input. Outputs such as 14.0 will be judged as incorrect.

Sample Input 2

10

Sample Output 2

1110


(defun main ()
  (let ((a (read)))
    (+ a (expt a 2) (expt a 3))))

(format t "~a~%" (main))


(let ((s1 (read-line))
      (s2 (read-line)))
  (format t "~A~%" (loop for c1 across s1
                         for c2 across s2
                         count (not (eql c1 c2)))))

Score : 200 points

Problem Statement

Given are strings S and T. Consider changing S to T by repeating the operation below. Find the minimum number of operations required to do so.

Operation: Choose one character of S and replace it with a different character.

Constraints

S and T have lengths between 1 and 2\times 10^5 (inclusive).

S and T consists of lowercase English letters.

S and T have equal lengths.

Input

Input is given from Standard Input in the following format:

S
T

Output

Print the answer.

Sample Input 1

cupofcoffee
cupofhottea

Sample Output 1

4

We can achieve the objective in four operations, such as the following:

First, replace the sixth character c with h.

Second, replace the eighth character f with t.

Third, replace the ninth character f with t.

Fourth, replace the eleventh character e with a.

Sample Input 2

abcde
bcdea

Sample Output 2

5

Sample Input 3

apple
apple

Sample Output 3

0

No operations may be needed to achieve the objective.


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(defmacro xor (form1 form2)
  (let ((f1 (gensym)) (f2 (gensym)))
    `(let ((,f1 ,form1)
           (,f2 ,form2))
       (if ,f1 (not ,f2) ,f2))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun test (a1 a2)
  (loop for x from 0 to a1
        for value = (logxor (- a1 x) (+ a2 x))
        do ;; (format t "~10,'0B~%" value)
           (println value)
           ;; (format t "~D ~D: ~8,'0B~%" (- a1 x) (+ a2 x) value)
        ))

(defun solve (a1 a2 rhs &optional (length 40))
  (declare (uint62 a1 a2 rhs))
  (labels ((dfs (pos value1)
             (declare ((integer -1 40) pos)
                      (uint62 value1))
             (dbg pos value1)
             (let* ((k (- a1 value1))
                    (value2 (+ a2 k)))
               (declare (uint62 value2))
               (when (= pos -1)
                 (if (and (> value1 0)
                          (= (logxor value1 value2) rhs))
                     (return-from solve value1)
                     (return-from dfs)))
               (let* ((cut (dpb 0 (byte (+ pos 1) 0) value2))
                      (mask (ldb (byte 64 0) (lognot (- (ash (logand cut (- cut)) 1) 1)))))
                 ;; (format t "~64,'0B~%" value1)
                 ;; (format t "~64,'0B~%" value2)
                 ;; (format t "~64,'0B~%" mask)
                 (unless (= (logand mask (logxor value1 value2))
                            (logand mask rhs))
                   (return-from dfs)))
               ;; 次を1
               (let* ((next-value1 (+ value1 (ash 1 pos))))
                 ;; (dbg next-value1 next-value2)
                 (when (< next-value1 a1)
                   (dfs (- pos 1) next-value1)))
               (dbg value1 value2 k)

               ;; 次を0
               (dfs (- pos 1) value1))))
    (dfs (- length 1) 0)))

(defun main ()
  (let* ((n (read))
         (as (make-array n :element-type 'uint62 :initial-element 0)))
    (dotimes (i n)
      (setf (aref as i) (read)))
    (let ((a1 (aref as 0))
          (a2 (aref as 1))
          (d (reduce #'logxor as :start 2 :initial-value 0)))
      (dbg a1 a2 d)
      (let ((res (solve a1 a2 d 41)))
        (println
         (if res
             (- a1 res)
             -1))))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
5 3
"
    "1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
3 5
"
    "-1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3
1 1 2
"
    "-1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "8
10 9 8 7 6 5 4 3
"
    "3
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3
4294967297 8589934593 12884901890
"
    "1
")))

Score : 600 points

Problem Statement

There are N piles of stones. The i-th pile has A_i stones.

Aoki and Takahashi are about to use them to play the following game:

Starting with Aoki, the two players alternately do the following operation:

Operation: Choose one pile of stones, and remove one or more stones from it.

When a player is unable to do the operation, he loses, and the other player wins.

When the two players play optimally, there are two possibilities in this game: the player who moves first always wins, or the player who moves second always wins, only depending on the initial number of stones in each pile.

In such a situation, Takahashi, the second player to act, is trying to guarantee his win by moving at least zero and at most (A_1 - 1) stones from the 1-st pile to the 2-nd pile before the game begins.

If this is possible, print the minimum number of stones to move to guarantee his victory; otherwise, print -1 instead.

Constraints

2 \leq N \leq 300

1 \leq A_i \leq 10^{12}

Input

Input is given from Standard Input in the following format:

N
A_1 \ldots A_N

Output

Print the minimum number of stones to move to guarantee Takahashi's win; otherwise, print -1 instead.

Sample Input 1

2
5 3

Sample Output 1

1

Without moving stones, if Aoki first removes 2 stones from the 1-st pile, Takahashi cannot win in any way.

If Takahashi moves 1 stone from the 1-st pile to the 2-nd before the game begins so that both piles have 4 stones, Takahashi can always win by properly choosing his actions.

Sample Input 2

2
3 5

Sample Output 2

-1

It is not allowed to move stones from the 2-nd pile to the 1-st.

Sample Input 3

3
1 1 2

Sample Output 3

-1

It is not allowed to move all stones from the 1-st pile.

Sample Input 4

8
10 9 8 7 6 5 4 3

Sample Output 4

3

Sample Input 5

3
4294967297 8589934593 12884901890

Sample Output 5

1

Watch out for overflows.


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(defmacro xor (form1 form2)
  (let ((f1 (gensym)) (f2 (gensym)))
    `(let ((,f1 ,form1)
           (,f2 ,form2))
       (if ,f1 (not ,f2) ,f2))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun test (a1 a2)
  (loop for x from 0 to a1
        for value = (logxor (- a1 x) (+ a2 x))
        do ;; (format t "~10,'0B~%" value)
           (println value)
           ;; (format t "~D ~D: ~8,'0B~%" (- a1 x) (+ a2 x) value)
        ))

(defun solve (a1 a2 rhs &optional (length 40))
  (declare #.OPT
           (uint62 a1 a2 rhs))
  (labels ((dfs (pos value1)
             (declare ((integer -1 40) pos)
                      (uint62 value1))
             (dbg pos value1)
             (let* ((k (- a1 value1))
                    (value2 (+ a2 k)))
               (declare (uint62 value2))
               (when (= pos -1)
                 (if (and (> value1 0)
                          (= (logxor value1 value2) rhs))
                     (return-from solve value1)
                     (return-from dfs)))
               (let* ((cut (dpb 0 (byte pos 0) value2))
                      (mask (ldb (byte 64 0) (lognot (- (ash (logand cut (- cut)) 1) 1)))))
                 ;; (format t "~64,'0B~%" value1)
                 ;; (format t "~64,'0B~%" value2)
                 ;; (format t "~64,'0B~%" mask)
                 (unless (= (logand mask (logxor value1 value2))
                            (logand mask rhs))
                   (return-from dfs)))
               ;; 次を1
               (let* ((next-value1 (+ value1 (ash 1 pos))))
                 ;; (dbg next-value1 next-value2)
                 (when (< next-value1 a1)
                   (dfs (- pos 1) next-value1)))
               (dbg value1 value2 k)
               ;; 次を0
               (dfs (- pos 1) value1))))
    (dfs (- length 1) 0)))

(defun main ()
  (let* ((n (read))
         (as (make-array n :element-type 'uint62 :initial-element 0)))
    (dotimes (i n)
      (setf (aref as i) (read)))
    (let ((a1 (aref as 0))
          (a2 (aref as 1))
          (d (reduce #'logxor as :start 2 :initial-value 0)))
      (dbg a1 a2 d)
      (let ((res (solve a1 a2 d 40)))
        (println
         (if res
             (- a1 res)
             -1))))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
5 3
"
    "1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
3 5
"
    "-1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3
1 1 2
"
    "-1
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "8
10 9 8 7 6 5 4 3
"
    "3
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3
4294967297 8589934593 12884901890
"
    "1
")))


(defun input ()
  (coerce (read-line) 'character))

(defun cap? (code)
  (cond ((< code 91) t)
		(t nil)))

(defun main ()
  (let* ((chr (input))
		(code (char-code chr)))
	(if (cap? code)
	  (format t "A~%")
	  (format t "a~%")
	  )))

(main)

Score : 100 points

Problem Statement

An uppercase or lowercase English letter \alpha will be given as input.
If \alpha is uppercase, print A; if it is lowercase, print a.

Constraints

\alpha is an uppercase (A - Z) or lowercase (a - z) English letter.

Input

Input is given from Standard Input in the following format:

α

Output

If \alpha is uppercase, print A; if it is lowercase, print a.

Sample Input 1

B

Sample Output 1

A

B is uppercase, so we should print A.

Sample Input 2

a

Sample Output 2

a

a is lowercase, so we should print a.


(defun app ()
    (let* ((a (string (read-char)))
        (num (char-code (coerce a 'character))))

    (if (> 96 num)
    (format t "A")
    (format t "~(a~)")
    )
    )
)
(app )


(defun letter-check (string)
  (string= (string-upcase string) string)
  )

(defun solve (string)
  (if (letter-check string)
      (princ "A")
      (princ "a")
  )
)
 (solve (read))


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defun main ()
  (let* ((n (read)))
    (sb-int:named-let dfs ((x (- n 1)) (res nil))
      (if (<= 0 x 25)
          (loop for d in (cons x res)
                do (write-char (code-char (+ 97 d)))
                finally (terpri))
          (multiple-value-bind (quot rem) (floor x 26)
            (dfs (- quot 1) (cons rem res)))))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "2
"
    "b
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "27
"
    "aa
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "123456789
"
    "jjddja
")))

Score : 300 points

Problem Statement

1000000000000001 dogs suddenly appeared under the roof of Roger's house, all of which he decided to keep. The dogs had been numbered 1 through 1000000000000001, but he gave them new names, as follows:

the dogs numbered 1,2,\cdots,26 were respectively given the names a, b, ..., z;

the dogs numbered 27,28,29,\cdots,701,702 were respectively given the names aa, ab, ac, ..., zy, zz;

the dogs numbered 703,704,705,\cdots,18277,18278 were respectively given the names aaa, aab, aac, ..., zzy, zzz;

the dogs numbered 18279,18280,18281,\cdots,475253,475254 were respectively given the names aaaa, aaab, aaac, ..., zzzy, zzzz;

the dogs numbered 475255,475256,\cdots were respectively given the names aaaaa, aaaab, ...;

and so on.

To sum it up, the dogs numbered 1, 2, \cdots were respectively given the following names:

a, b, ..., z, aa, ab, ..., az, ba, bb, ..., bz, ..., za, zb, ..., zz, aaa, aab, ..., aaz, aba, abb, ..., abz, ..., zzz, aaaa, ...

Now, Roger asks you:

"What is the name for the dog numbered N?"

Constraints

N is an integer.

1 \leq N \leq 1000000000000001

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer to Roger's question as a string consisting of lowercase English letters.

Sample Input 1

2

Sample Output 1

b

Sample Input 2

27

Sample Output 2

aa

Sample Input 3

123456789

Sample Output 3

jjddja


(defun get-length (n m)
  (if (<= (expt 26 (1- m)) n (expt 26 m))
      m
      (get-length n (1+ m))))

(let* ((n (read))
       (l (get-length n 1))
       (min (/ (1- (expt 26 l)) 25))
       (m (- n min)))
  (loop :for i :from l :downto 1
        :do (multiple-value-bind (x y) (floor m (expt 26 (1- i)))
              (format t "~A" (code-char (+ 97 x)))
              (setf m y))))
(format t "~%")


(defun red-scarf(n a)
  (let* ((total_xor (reduce #'logxor a)))
    (loop for i from 0 below n
          collect (logxor (aref a i) total_xor))))

(defun create-data ()
  (let* ((n (read))
         (a (make-array `(,n))))
    (dotimes (i n)
      (setf (aref a i) (read)))
    (values n a)))

(multiple-value-bind (n a) (create-data)
  (format t "~{~a ~}~%" (red-scarf n a)))

Score : 500 points

Problem Statement

There are N Snuke Cats numbered 1, 2, \ldots, N, where N is even.

Each Snuke Cat wears a red scarf, on which his favorite non-negative integer is written.

Recently, they learned the operation called xor (exclusive OR).

What is xor?

For n non-negative integers x_1, x_2, \ldots, x_n, their xor, x_1~\textrm{xor}~x_2~\textrm{xor}~\ldots~\textrm{xor}~x_n is defined as follows:

When x_1~\textrm{xor}~x_2~\textrm{xor}~\ldots~\textrm{xor}~x_n is written in base two, the digit in the 2^k's place (k \geq 0) is 1 if the number of integers among x_1, x_2, \ldots, x_n whose binary representations have 1 in the 2^k's place is odd, and 0 if that count is even.

For example, 3~\textrm{xor}~5 = 6.

They wanted to use this operation quickly, so each of them calculated the xor of the integers written on their scarfs except his scarf.

We know that the xor calculated by Snuke Cat i, that is, the xor of the integers written on the scarfs except the scarf of Snuke Cat i is a_i.
Using this information, restore the integer written on the scarf of each Snuke Cat.

Constraints

All values in input are integers.

2 \leq N \leq 200000

N is even.

0 \leq a_i \leq 10^9

There exists a combination of integers on the scarfs that is consistent with the given information.

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 \ldots a_N

Output

Print a line containing N integers separated with space.

The i-th of the integers from the left should represent the integer written on the scarf of Snuke Cat i.

If there are multiple possible solutions, you may print any of them.

Sample Input 1

4
20 11 9 24

Sample Output 1

26 5 7 22

5~\textrm{xor}~7~\textrm{xor}~22 = 20

26~\textrm{xor}~7~\textrm{xor}~22 = 11

26~\textrm{xor}~5~\textrm{xor}~22 = 9

26~\textrm{xor}~5~\textrm{xor}~7 = 24

Thus, this output is consistent with the given information.


#-swank
(unless (member :child-sbcl *features*)
  "I refered from https://competitive12.blogspot.com/2020/03/common-lisp.html thank you!"
  (quit
   :unix-status
   (process-exit-code
    (run-program *runtime-pathname*
                 `("--control-stack-size" "128MB"
                   "--noinform" "--disable-ldb" "--lose-on-corruption" "--end-runtime-options"
                   "--eval" "(push :child-sbcl *features*)"
                   "--script" ,(namestring *load-pathname*))
                 :output t :error t :input t))))
#-swank
(unless (member :child-sbcl *features*)
  "I refered from https://competitive12.blogspot.com/2020/03/common-lisp.html thank you!"
  (quit
   :unix-status
   (process-exit-code
    (run-program *runtime-pathname*
                 `("--control-stack-size" "256MB"
                   "--noinform" "--disable-ldb" "--lose-on-corruption" "--end-runtime-options"
                   "--eval" "(push :child-sbcl *features*)"
                   "--script" ,(namestring *load-pathname*))
                 :output t :error t :input t))))
(defmacro dpline (name args memo-size &body body)
  (let ((memo (gensym)))
    `(let ((,memo (make-array ,memo-size :initial-element nil)))
       (defun ,name ,args
         (or (aref ,memo ,@args)
             (setf (aref ,memo ,@args)
                   ,@body))))))

(defmacro dphash (name args &body expr)
  `(let ((table (make-hash-table :test #'equal)))
     (defun  ,name ,args
       (or (gethash (list ,@args) table)
           (setf (gethash (list ,@args) table)
                 (progn
                   ,@expr))))))

(defun split (x str)
  (let ((pos (search x str))
        (size (length x)))
    (if pos
        (cons (subseq str 0 pos)
              (split x (subseq str (+ pos size))))
        (list str))))

(defmacro collect-times (time body)
  `(loop repeat ,time collect ,body))

(defun read-times (time)
  (collect-times time (read)))

(defmacro aif (expr then else)
  `(let ((it ,expr))
     (if it ,then ,else)))

(defmacro awhen (expr &rest then)
  `(aif ,expr (progn ,@then) nil))

(defun comulative (function list &key base)
  (if base
      (comulative function (cons base list))
      (do ((lst (cdr list) (cdr lst))
           (acc (list (car list))))
          ((null lst) (reverse acc))
        (push (funcall function (car acc) (car lst)) acc))))

(defun binary-search (function left right
                      &optional
                        (eps 1)
                        (average-function (lambda (x y) (ash (+ x y) -1))))
  (if (<= (abs (- left right)) eps)
      right
      (let ((mid (funcall average-function left right)))
        (if (funcall function mid)
            (binary-search function left mid eps average-function)
            (binary-search function mid right eps average-function)))))

(defun arithmetic-mean (&rest body)
  (/ (apply #'+ body) (length body)))

(defvar +MOD+ (+ (expt 10 9) 7))

(defun range-0-n (n &optional (step 1))
  (loop for i from 0 below n by step collect i))

(defun range-1-n (n &optional (step 1))
  (loop for i from 1 below n by step collect i))

(defun range-a-b (a b &optional (step 1))
  (loop for i from a below b by step collect i))

(defun map-0-n (function n &optional (step 1))
  (mapcar function (range-0-n n step)))

(defun map-1-n (function n &optional (step 1))
  (mapcar function (range-1-n n step)))

(defun map-a-b (function a b &optional (step 1))
  (mapcar function (range-a-b a b step)))

(defun read-string (&optional (stream *standard-input*))
  (labels ((is-empty (x)
             (or (char= x #\space) (char= x #\newline))))
    (loop for char = (read-char stream)
          with result
          when (and result (is-empty char))
            do (return (concatenate 'string (nreverse result)))
          when (null (is-empty char))
            do (push char result))))

(defun merge-sort (lst &optional (compare #'<))
  (let ((turn 0))
    (labels ((merge-list (a b a-length b-length)
               (cond ((zerop a-length) b)
                     ((zerop b-length) a)
                     ((funcall compare (car b) (car a))
                      (incf turn a-length)
                      (cons (car b)
                            (merge-list a (cdr b) a-length (1- b-length))))
                     (t
                      (cons (car a)
                            (merge-list (cdr a) b (1- a-length) b-length)))))
             (f (lst length)
               (if (= length 1)
                   lst
                   (let ((mid (ash length -1)))
                     (merge-list (f (subseq lst 0 mid) mid)
                                 (f (subseq lst mid) (- length mid))
                                 mid
                                 (- length mid))))))
      (values (f lst (length lst)) turn))))

(defun group (lst &optional (test #'eql) (key nil))
  (let ((table (make-hash-table :test test)))
    (mapc (lambda (x)
            (push x (gethash (if key (funcall key x) x) table)))
          lst)
    (loop for value being each hash-value in table
          collect value)))

(defun nearby (&rest args)
  (let ((current (subseq args 0 (ash (length args) -1)))
        (validator (subseq args (ash (length args) -1)))
        (res nil))
    (labels ((check ()
               (every (lambda (x y) (and (<= 0 x) (< x y)))
                      current validator))
             (f (lst)
               (unless lst (return-from f))
               (let ((x (car lst)))
                 (setf (car lst) (1+ x))
                 (when (check) (push (copy-list current) res))
                 (setf (car lst) (1- x))
                 (when (check) (push (copy-list current) res))
                 (setf (car lst) x))
               (f (cdr lst))))
      (f current)
      res)))

(princ (1+ (position 0 (read-times 5))))

Score : 100 points

Problem Statement

We have five variables x_1, x_2, x_3, x_4, and x_5.

The variable x_i was initially assigned a value of i.

Snuke chose one of these variables and assigned it 0.

You are given the values of the five variables after this assignment.

Find out which variable Snuke assigned 0.

Constraints

The values of x_1, x_2, x_3, x_4, and x_5 given as input are a possible outcome of the assignment by Snuke.

Input

Input is given from Standard Input in the following format:

x_1 x_2 x_3 x_4 x_5

Output

If the variable Snuke assigned 0 was x_i, print the integer i.

Sample Input 1

0 2 3 4 5

Sample Output 1

1

In this case, Snuke assigned 0 to x_1, so we should print 1.

Sample Input 2

1 2 0 4 5

Sample Output 2

3


(defun main (x y)
  (and (<= (* 2 x) y)
       (<= y (* 4 x))))

(princ (if (main (read) (read)) "Yes" "No"))

Score : 200 points

Problem Statement

There are some animals in a garden. Each of them is a crane with two legs or a turtle with four legs.

Takahashi says: "there are X animals in total in the garden, and they have Y legs in total." Determine whether there is a combination of numbers of cranes and turtles in which this statement is correct.

Constraints

1 \leq X \leq 100

1 \leq Y \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

X Y

Output

If there is a combination of numbers of cranes and turtles in which the statement is correct, print Yes; otherwise, print No.

Sample Input 1

3 8

Sample Output 1

Yes

The statement "there are 3 animals in total in the garden, and they have 8 legs in total" is correct if there are two cranes and one turtle. Thus, there is a combination of numbers of cranes and turtles in which the statement is correct.

Sample Input 2

2 100

Sample Output 2

No

There is no combination of numbers of cranes and turtles in which this statement is correct.

Sample Input 3

1 2

Sample Output 3

Yes

We also consider the case in which there are only cranes or only turtles.


(declaim (inline calc))
(defun calc (x y)
  (let ((diff (- y (* x 2))))
    (cond ((= diff 0)
           "Yes")
          ((= x (+ diff (/ diff 2)))
           "Yes")
          (t "No"))))

(princ (calc (read) (read)))


(let* ((n (read))
       (m (read)))
  (loop :for k :from 0 :upto n
        :for j := (- n k)
        :if (= m (+ (* k 2) (* j 4)))
          :do(princ "Yes") :and :return 1
        :finally (princ "No")))


(let* ((n (read))
       (m (read))
       (lst (loop :repeat m :collect (read))))
  (loop :for k :from 0
        :for j := (if (oddp k)
                      (+ n (- (/ (1+ k) 2)))
                      (+ n (/ k 2)))
        :if (not (position j lst))
          :do (princ j) :and :return 1))

Score : 300 points

Problem Statement

Given are an integer X and an integer sequence of length N: p_1, \ldots, p_N.

Among the integers not contained in the sequence p_1, \ldots, p_N (not necessarily positive), find the integer nearest to X, that is, find the integer whose absolute difference with X is the minimum. If there are multiple such integers, report the smallest such integer.

Constraints

1 \leq X \leq 100

0 \leq N \leq 100

1 \leq p_i \leq 100

p_1, \ldots, p_N are all distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

X N
p_1 ... p_N

Output

Print the answer.

Sample Input 1

6 5
4 7 10 6 5

Sample Output 1

8

Among the integers not contained in the sequence 4, 7, 10, 6, 5, the one nearest to 6 is 8.

Sample Input 2

10 5
4 7 10 6 5

Sample Output 2

9

Among the integers not contained in the sequence 4, 7, 10, 6, 5, the ones nearest to 10 are 9 and 11. We should print the smaller one, 9.

Sample Input 3

100 0

Sample Output 3

100

When N = 0, the second line in the input will be empty. Also, as seen here, X itself can be the answer.


(eval-when (:compile-toplevel :load-toplevel :execute)
  (sb-int:defconstant-eqx opt
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0))
    #'equal)
  #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t)
  #-swank (set-dispatch-macro-character
           #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t)))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
;;;
;;; Queue with singly linked list
;;;

(defstruct (queue (:constructor make-queue
                      (&optional list &aux (tail (last list)))))
  (list nil :type list)
  (tail nil :type list))

(declaim (inline enqueue))
(defun enqueue (obj queue)
  "Pushes OBJ to the end of QUEUE."
  (symbol-macrolet ((list (queue-list queue))
                    (tail (queue-tail queue)))
    (if (null list)
        (setf tail (list obj)
              list tail)
        (setf (cdr tail) (list obj)
              tail (cdr tail))))
  queue)

(declaim (inline dequeue))
(defun dequeue (queue)
  "Removes and returns the element at the front of QUEUE. Returns NIL if QUEUE
is empty."
  (pop (queue-list queue)))

(declaim (inline queue-empty-p))
(defun queue-empty-p (queue)
  (null (queue-list queue)))

(declaim (inline queue-peek))
(defun queue-peek (queue)
  (car (queue-list queue)))

(declaim (inline enqueue-front))
(defun enqueue-front (obj queue)
  "Pushes OBJ to the front of QUEUE."
  (symbol-macrolet ((list (queue-list queue))
                    (tail (queue-tail queue)))
    (if (null list)
        (setf tail (list obj)
              list tail)
        (push obj list))
    queue))

(declaim (inline read-schar))
(defun read-schar (&optional (stream *standard-input*))
  (declare #-swank (sb-kernel:ansi-stream stream)
           (inline read-byte))
  #+swank (read-char stream nil #\Newline) ; on SLIME
  #-swank (code-char (read-byte stream nil #.(char-code #\Newline))))

(in-package :cl-user)

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 1000000007)

;;;
;;; Body
;;;

(defconstant +inf+ #xffffffff)

(defun main ()
  (let* ((h (read))
         (w (read))
         (k (read))
         (start-x (- (read) 1))
         (start-y (- (read) 1))
         (goal-x (- (read) 1))
         (goal-y (- (read) 1))
         (plan (make-array (list h w) :element-type 'bit :initial-element 0))
         (marked (make-array (list h w 4) :element-type 'bit :initial-element 0))
         (dists (make-array (list h w) :element-type 'uint32 :initial-element +inf+))
         ;; x . y
         (que (make-queue)))
    (declare (uint31 h w k))
    (dotimes (i h)
      (dotimes (j w (read-schar))
        (ecase (read-schar)
          (#\@ (setf (aref plan i j) 1))
          (#\.))))
    (enqueue (cons start-x start-y) que)
    ;; up:0, down:1, left:2, right:3
    (setf (aref dists start-x start-y) 0)
    (setf (aref marked start-x start-y 0) 1
          (aref marked start-x start-y 1) 1
          (aref marked start-x start-y 2) 1
          (aref marked start-x start-y 3) 1)
    (loop until (queue-empty-p que)
          for (x . y) of-type (uint31 . uint31) = (dequeue que)
          for dist = (aref dists x y)
          do ;; up
             (loop for delta from 1 to k
                   for new-x = (- x delta)
                   while (and (>= new-x 0)
                              (zerop (aref marked new-x y 0))
                              (zerop (aref plan new-x y)))
                   do (setf (aref marked new-x y 0) 1)
                   when (< (+ dist 1) (aref dists new-x y))
                   do (setf (aref dists new-x y) (+ dist 1))
                      (enqueue (cons new-x y) que))
             ;; down
             (loop for delta from 1 to k
                   for new-x = (+ x delta)
                   while (and (< new-x h)
                              (zerop (aref marked new-x y 1))
                              (zerop (aref plan new-x y)))
                   do (setf (aref marked new-x y 1) 1)
                   when (< (+ dist 1) (aref dists new-x y))
                   do (setf (aref dists new-x y) (+ dist 1))
                      (enqueue (cons new-x y) que))
             ;; left
             (loop for delta from 1 to k
                   for new-y = (- y delta)
                   while (and (>= new-y 0)
                              (zerop (aref marked x new-y 2))
                              (zerop (aref plan x new-y)))
                   do (setf (aref marked x new-y 2) 1)
                   when (< (+ dist 1) (aref dists x new-y))
                   do (setf (aref dists x new-y) (+ dist 1))
                      (enqueue (cons x new-y) que))
             ;; right
             (loop for delta from 1 to k
                   for new-y = (+ y delta)
                   while (and (< new-y w)
                              (zerop (aref marked x new-y 3))
                              (zerop (aref plan x new-y)))
                   do (setf (aref marked x new-y 3) 1)
                   when (< (+ dist 1) (aref dists x new-y))
                   do (setf (aref dists x new-y) (+ dist 1))
                      (enqueue (cons x new-y) que)))
    (let ((res (aref dists goal-x goal-y)))
      (println
       (if (= res +inf+)
           -1
           res)))))

(defun main ()
  (declare #.OPT)
  (let* ((h (read))
         (w (read))
         (k (read))
         (boundary (if (>= k 100000) 100000 0))
         (start-x (- (read) 1))
         (start-y (- (read) 1))
         (goal-x (- (read) 1))
         (goal-y (- (read) 1))
         (plan (make-array (list h w) :element-type 'bit :initial-element 0))
         ;; 既に〇〇進んだ
         (marked (make-array (list h w 4) :element-type 'int32 :initial-element -1))
         (dists (make-array (list h w) :element-type 'uint32 :initial-element +inf+))
         ;; x . y
         (que (make-queue)))
    (declare (uint31 h w k))
    (dotimes (i h)
      (dotimes (j w (read-schar))
        (ecase (read-schar)
          (#\@ (setf (aref plan i j) 1))
          (#\.))))
    (if (<= boundary 100000)
        (progn
          (fill (array-storage-vector marked) 0)
          (enqueue (cons start-x start-y) que)
          ;; up:0, down:1, left:2, right:3
          (setf (aref dists start-x start-y) 0)
          (setf (aref marked start-x start-y 0) 1
                (aref marked start-x start-y 1) 1
                (aref marked start-x start-y 2) 1
                (aref marked start-x start-y 3) 1)
          (loop until (queue-empty-p que)
                for (x . y) of-type (uint31 . uint31) = (dequeue que)
                for dist = (aref dists x y)
                do ;; up
                   (loop for delta from 1 to k
                         for new-x = (- x delta)
                         while (and (>= new-x 0)
                                    (zerop (aref marked new-x y 0))
                                    (zerop (aref plan new-x y)))
                         do (setf (aref marked new-x y 0) 1)
                         when (< (+ dist 1) (aref dists new-x y))
                         do (setf (aref dists new-x y) (+ dist 1))
                            (enqueue (cons new-x y) que))
                   ;; down
                   (loop for delta from 1 to k
                         for new-x = (+ x delta)
                         while (and (< new-x h)
                                    (zerop (aref marked new-x y 1))
                                    (zerop (aref plan new-x y)))
                         do (setf (aref marked new-x y 1) 1)
                         when (< (+ dist 1) (aref dists new-x y))
                         do (setf (aref dists new-x y) (+ dist 1))
                            (enqueue (cons new-x y) que))
                   ;; left
                   (loop for delta from 1 to k
                         for new-y = (- y delta)
                         while (and (>= new-y 0)
                                    (zerop (aref marked x new-y 2))
                                    (zerop (aref plan x new-y)))
                         do (setf (aref marked x new-y 2) 1)
                         when (< (+ dist 1) (aref dists x new-y))
                         do (setf (aref dists x new-y) (+ dist 1))
                            (enqueue (cons x new-y) que))
                   ;; right
                   (loop for delta from 1 to k
                         for new-y = (+ y delta)
                         while (and (< new-y w)
                                    (zerop (aref marked x new-y 3))
                                    (zerop (aref plan x new-y)))
                         do (setf (aref marked x new-y 3) 1)
                         when (< (+ dist 1) (aref dists x new-y))
                         do (setf (aref dists x new-y) (+ dist 1))
                            (enqueue (cons x new-y) que)))
          (progn
            (enqueue (cons start-x start-y) que)
            ;; up:0, down:1, left:2, right:3
            (setf (aref dists start-x start-y) 0)
            (setf (aref marked start-x start-y 0) k
                  (aref marked start-x start-y 1) k
                  (aref marked start-x start-y 2) k
                  (aref marked start-x start-y 3) k)
            (loop until (queue-empty-p que)
                  for (x . y) of-type (uint31 . uint31) = (dequeue que)
                  for dist = (aref dists x y)
                  do ;; up
                     ;; #>marked
                     (setf (aref marked x y 0) k
                           (aref marked x y 1) k
                           (aref marked x y 2) k
                           (aref marked x y 3) k)
                     (loop for delta from 1 to k
                           for new-x = (- x delta)
                           while (and (>= new-x 0)
                                      ;; あとk-deltaだけ進めるが、既にそれ以上に進んでいたら打ち切れる
                                      (> (- k delta) (aref marked new-x y 0))
                                      (zerop (aref plan new-x y)))
                           do (setf (aref marked new-x y 0) (- k delta))
                           when (< (+ dist 1) (aref dists new-x y))
                           do (setf (aref dists new-x y) (+ dist 1))
                              (enqueue (cons new-x y) que))
                     ;; down
                     (loop for delta from 1 to k
                           for new-x = (+ x delta)
                           while (and (< new-x h)
                                      (>= (- k delta) (aref marked new-x y 1))
                                      (zerop (aref plan new-x y)))
                           do (setf (aref marked new-x y 1) (- k delta))
                           when (< (+ dist 1) (aref dists new-x y))
                           do (setf (aref dists new-x y) (+ dist 1))
                              (enqueue (cons new-x y) que))
                     ;; left
                     (loop for delta from 1 to k
                           for new-y = (- y delta)
                           while (and (>= new-y 0)
                                      (>= (- k delta) (aref marked x new-y 2))
                                      (zerop (aref plan x new-y)))
                           do (setf (aref marked x new-y 2) (- k delta))
                           when (< (+ dist 1) (aref dists x new-y))
                           do (setf (aref dists x new-y) (+ dist 1))
                              (enqueue (cons x new-y) que))
                     ;; right
                     (loop for delta from 1 to k
                           for new-y = (+ y delta)
                           while (and (< new-y w)
                                      (>= (- k delta) (aref marked x new-y 3))
                                      (zerop (aref plan x new-y)))
                           do (setf (aref marked x new-y 3) (- k delta))
                           when (< (+ dist 1) (aref dists x new-y))
                           do (setf (aref dists x new-y) (+ dist 1))
                              (enqueue (cons x new-y) que))))))
    (let ((res (aref dists goal-x goal-y)))
      (println
       (if (= res +inf+)
           -1
           res)))))

#-swank (main)

;;;
;;; Test and benchmark
;;;

#+swank
(defun io-equal (in-string out-string &key (function #'main) (test #'equal))
  "Passes IN-STRING to *STANDARD-INPUT*, executes FUNCTION, and returns true if
the string output to *STANDARD-OUTPUT* is equal to OUT-STRING."
  (labels ((ensure-last-lf (s)
             (if (eql (uiop:last-char s) #\Linefeed)
                 s
                 (uiop:strcat s uiop:+lf+))))
    (funcall test
             (ensure-last-lf out-string)
             (with-output-to-string (out)
               (let ((*standard-output* out))
                 (with-input-from-string (*standard-input* (ensure-last-lf in-string))
                   (funcall function)))))))

#+swank
(defun get-clipbrd ()
  (with-output-to-string (out)
    (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t)))

#+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname))
#+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*))

#+swank
(defun run (&optional thing (out *standard-output*))
  "THING := null | string | symbol | pathname

null: run #'MAIN using the text on clipboard as input.
string: run #'MAIN using the string as input.
symbol: alias of FIVEAM:RUN!.
pathname: run #'MAIN using the text file as input."
  (let ((*standard-output* out))
    (etypecase thing
      (null
       (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd)))
         (main)))
      (string
       (with-input-from-string (*standard-input* (delete #\Return thing))
         (main)))
      (symbol (5am:run! thing))
      (pathname
       (with-open-file (*standard-input* thing)
         (main))))))

#+swank
(defun gen-dat ()
  (uiop:with-output-file (out *dat-pathname* :if-exists :supersede)
    (format out "")))

#+swank
(defun bench (&optional (out (make-broadcast-stream)))
  (time (run *dat-pathname* out)))

;; To run: (5am:run! :sample)
#+swank
(it.bese.fiveam:test :sample
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3 5 2
3 2 3 4
.....
.@..@
..@..
"
    "5
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "1 6 4
1 1 1 6
......
"
    "2
"))
  (it.bese.fiveam:is
   (common-lisp-user::io-equal "3 3 1
2 1 2 3
.@.
.@.
.@.
"
    "-1
")))

Score : 600 points

Problem Statement

Snuke, a water strider, lives in a rectangular pond that can be seen as a grid with H east-west rows and W north-south columns. Let (i,j) be the square at the i-th row from the north and j-th column from the west.

Some of the squares have a lotus leaf on it and cannot be entered.
The square (i,j) has a lotus leaf on it if c_{ij} is @, and it does not if c_{ij} is ..

In one stroke, Snuke can move between 1 and K squares (inclusive) toward one of the four directions: north, east, south, and west.
The move may not pass through a square with a lotus leaf. Moving to such a square or out of the pond is also forbidden.

Find the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2).
If the travel from (x_1,y_1) to (x_2,y_2) is impossible, point out that fact.

Constraints

1 \leq H,W,K \leq 10^6

H \times W \leq 10^6

1 \leq x_1,x_2 \leq H

1 \leq y_1,y_2 \leq W

x_1 \neq x_2 or y_1 \neq y_2.

c_{i,j} is . or @.

c_{x_1,y_1} = .

c_{x_2,y_2} = .

All numbers in input are integers.

Input

Input is given from Standard Input in the following format:

H W K
x_1 y_1 x_2 y_2
c_{1,1}c_{1,2} .. c_{1,W}
c_{2,1}c_{2,2} .. c_{2,W}
:
c_{H,1}c_{H,2} .. c_{H,W}

Output

Print the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2), or print -1 if the travel is impossible.

Sample Input 1

3 5 2
3 2 3 4
.....
.@..@
..@..

Sample Output 1

5

Initially, Snuke is at the square (3,2).
He can reach the square (3, 4) by making five strokes as follows:

From (3, 2), go west one square to (3, 1).

From (3, 1), go north two squares to (1, 1).

From (1, 1), go east two squares to (1, 3).

From (1, 3), go east one square to (1, 4).

From (1, 4), go south two squares to (3, 4).

Sample Input 2

1 6 4
1 1 1 6
......

Sample Output 2

2

Sample Input 3

3 3 1
2 1 2 3
.@.
.@.
.@.

Sample Output 3

-1