#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = atcoder::modint998244353;
// using mint = double;

#define rep(i, l, r) for (int i = (int)(l); i<(int)(r); i++)
#define ll long long
#define ld long double
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define siz(x) (int)(x).size()

template<class T> bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

const int inf = 1e9;
const ll INF = 4e18;

template<class T> using pq = priority_queue<T, vector<T>, less<T>>;
template<class T> using spq = priority_queue<T, vector<T>, greater<T>>;

vector<int> di = {0, 0, 1, -1};
vector<int> dj = {1, -1, 0, 0};

struct Edge {
    int to, cost;
};

//エラトステネスの篩による [1, N] の素数判定
vector<bool> primeSieve(int N) {
    vector<bool> isPrime(N+1, true);
    isPrime[0] = isPrime[1] = false;
    for (int i = 2; i <= N; i++) {
        if (isPrime[i]) {
            for (int j = 2*i; j <= N; j += i) isPrime[j] = false;
        }
    }
    return isPrime;
}

void solve() {
    ll N; cin >> N;
    int M = 100050;
    vector<bool> isprime = primeSieve(M);
    vector<ll> ans;
    rep(i, 1, M+1) {
        if (!isprime[i]) continue;
        ll now = (ll)i * i;
        while(now <= N) {
            ans.push_back(now);
            now *= i;
        }
    }
    sort(all(ans)); ans.erase(unique(all(ans)), ans.end());
    ll sum = 0;
    for (ll x : ans) sum += x;
    cout << sum << endl;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int T = 1;
    // cin >> T;
    while(T--) {
        solve();
    }
}