Datasets:

slayone
/

uva_spoj_raw

#include<bits/stdc++.h>

#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define tr(c,it) for(auto it = (c).begin(); it != (c).end(); it++)

using namespace std;

ll f(ll n){
	ll fac=0;
	for(ll i=1;i<=n;i++){
		if(n%i==0){
			fac+=1;
			/*if(n==6){
				cout<<"**"<<i<<"**"<<"\n";
			}*/
		}
	}
	if(fac%2==0){
		fac/=2;
	}
	else{
		fac = fac/2 + 1;
	}
	return fac;
}

void solve(){
	ll n;
	cin>>n;
	ll ans=0;
	for(ll i=1;i<=n;i++){
		//cout<<i<<"&&"<<f(i)<<"\n";
		ans += f(i);
	}
	cout<<ans<<"\n";
}

int main(){
	int t=1;
	//cin>>t;
	while(t--){
		solve();
	}
	return 0;
}

	#include<bits/stdc++.h>

	#define ll long long
	#define ull unsigned long long
	#define pb push_back
	#define mp make_pair
	#define tr(c,it) for(auto it = (c).begin(); it != (c).end(); it++)

	using namespace std;

	ll f(ll n){
	ll fac=0;
	for(ll i=1;i<=n;i++){
	if(n%i==0){
	fac+=1;
	/*if(n==6){
	cout<<""<<i<<""<<"\n";
	}*/
	}
	}
	if(fac%2==0){
	fac/=2;
	}
	else{
	fac = fac/2 + 1;
	}
	return fac;
	}

	void solve(){
	ll n;
	cin>>n;
	ll ans=0;
	for(ll i=1;i<=n;i++){
	//cout<<i<<"&&"<<f(i)<<"\n";
	ans += f(i);
	}
	cout<<ans<<"\n";
	}

	int main(){
	int t=1;
	//cin>>t;
	while(t--){
	solve();
	}
	return 0;
	}