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

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