#include <bits/stdc++.h>
using namespace std;

int main() {
  int64_t N;
  cin >> N;

  int64_t ans = 0;
  int64_t sn = 1;
  while (sn * sn < N) {
    if (N % sn == 0) {
      ans += sn;
      ans += N / sn;
    }
    ++sn;
  }

  if (sn * sn == N) ans += sn;
  cout << ans << endl;

  return 0;
}