#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  map<int, int> mp;
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      mp[i]++;
      n /= i;
    }
  }
  if (n > 1) mp[n]++;
  long long ans = 0;
  for (auto i : mp) {
    ans += i.first * i.second;
  }
  cout << ans << endl;
  return 0;
}