Datasets:

slayone
/

uva_spoj_raw

/*
   math > number theory
   difficulty: none
   date: none 
   by: @brpapa
*/
#include <iostream>
#include <queue>
#include <cmath>
using namespace std;

int main() {
   int n, qte = 0;
   cin >> n;

   for (int k = 1; k <= sqrt(n); k++)
      for (int i = k; i * k <= n; i++)
         qte++;

   cout << qte << endl;
   return 0;
}

	/*
	math > number theory
	difficulty: none
	date: none
	by: @brpapa
	*/
	#include <iostream>
	#include <queue>
	#include <cmath>
	using namespace std;

	int main() {
	int n, qte = 0;
	cin >> n;

	for (int k = 1; k <= sqrt(n); k++)
	for (int i = k; i * k <= n; i++)
	qte++;

	cout << qte << endl;
	return 0;
	}