#include <bits/stdc++.h>
using namespace std;
#define sorted(a) sort(a.begin(), a.end());
#define ALL(a) (a).begin(), (a).end()
#define rep(i, n) for (int i = 0; i < n; i++)
typedef long long ll;
const long mod = 1e9 + 7;

int main(void) {
#ifdef DEBUG
  freopen("input.txt", "r", stdin);
#endif

  ios_base::sync_with_stdio(false);
  cin.tie(0);

  ll N;
  cin >> N;
  ll ans = 0, n;
  n = sqrt(N);
  for (int i = 1; i <= n; i++) {
    if (N % i == 0) {
      ans += i;
      ans += N / i;
    }
  }
  cout << ans << endl;
  return 0;
}