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

int N;
ll ans = 0;

map<int, int> prime_factors(int n) {
  map<int, int> res;
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      res[i]++;
      n /= i;
    }
  }
  if (n != 1) res[n]++;
  return res;
}

int main() {
  cin >> N;
  auto res = prime_factors(N);
  for (auto p: res) {
    ans += (ll)p.first * p.second;
  }
  cout << ans << endl;
  return 0;
}