#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
typedef long long ll;
const int INF = 1<<30;
const ll INFLL = 1LL<<60;
//const ll MOD = 998244353;
const double INFD = 1.0E10;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, -1, 0, 1};
//const int dx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
//const int dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};
using Pair = pair<ll, ll>;
using Graph = vector<vector<ll>>;
using mint = atcoder::modint998244353;


int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
    
    ll n; cin >> n;
    vector<ll> primes;
    vector<bool> is_prime(1000000, true);
    is_prime[0] = false;
    is_prime[1] = false;
    for (int i = 2; i < 100000; i++){
        if (!is_prime[i]) continue;
        primes.push_back(i);
        for (int j = i * 2; j < 100000; j += i){
            is_prime[j] = false;
        }
    }
    
    ll ans = 0;
    for (auto p: primes){
        ll x = p;
        for (int i = 2; i < 60; i++){
            x *= p;
            if (x > n) break;
            ans += x;
        }
    }
    
    cout << ans << endl;
    
    
    return 0;
}