#include <bits/stdc++.h>
using namespace std;
using ll=long long;

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

    if(n<2||10000000000<n) return 1;

    for(ll x=2;x*x<=n;x++){
        ll y=2;
        while(0<x%y&&y*y<=x) y++;
        if(y<x&&x%y==0) continue;
        ll k=x*x;
        while(k<=n){
            sum+=k;
            k*=x;
        }
    }
    cout << sum << endl;
}