#include <bits/stdc++.h>
#include <atcoder/all>
typedef long long int ll;
using namespace atcoder;
using namespace std;
ll ans=0;

template <typename T>
struct PrimeSieve {
  int n, half;
  std::vector<bool> sieve;
  std::vector<T> prime_list;
  // sieve[i] ... 2 * i + 1

  PrimeSieve(T _n) : n(_n) {
    init();
  }

  void init() {
    if (n < 2) {
      return;
    }
    half = (n + 1) / 2;
    sieve.assign(half, true);
    sieve[0] = false;
    prime_list.emplace_back(2);
    for (long long i = 1; 2 * i + 1 <= n; ++i) {
      if (!sieve[i]) continue;
      T p = 2 * i + 1;
      prime_list.emplace_back(p);
      for (long long j = 2 * i * (i + 1); j < half; j += p) {
        sieve[j] = false;
      }
    }
  }

  bool isPrime(T x) {
    if (x == 2) return true;
    if (x % 2 == 0) return false;
    return sieve[x / 2];
  }

  T getPrimeCount() {
    return prime_list.size();
  }

  T getKthPrime(int k) {
    return prime_list[k];
  }
};

int main(){
  ll N;
  cin >> N;
  assert(2 <= N && N <= 10000000000);
  PrimeSieve<ll> ps(100000);
  for(auto x: ps.prime_list){
    ll x2 = x * x;
    while(x2 <= N){
      ans += x2;
      x2 *= x;
    }
  }
  cout << ans << endl;
  return 0;
}