#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); i++)
#define repr(i, n) for (int i = (n) - 1; i >= 0; i--)
#define range(a) a.begin(), a.end()

using namespace std;
using ll = long long;

int main() {
  ll n; cin >> n;
  ll ans = 0;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      ans += i;
      if (i * i != n) ans += n / i;
    }
  }
  cout << ans << endl;
}