#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    long long n;
    cin >> n;
    const int siz = 2e5;
    long long ans = 0;
    vector<int> isp(siz);
    isp[0] = isp[1] = 1;
    for (int i = 2; i < siz; ++i)
    {
        if (isp[i]) continue;
        for (int j = 2; i * j < siz; ++j) isp[i * j] = 1;
        long long tmp = (long long)i * i;
        while (tmp <= n)
        {
            ans += tmp;
            tmp *= i;
        }
    }
    cout << ans << endl;
}