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

vector<int64_t> divisors(int64_t n) {
  vector<int64_t> ret;
  for (int64_t i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      ret.push_back(i);
      if (n / i != i) {
        ret.push_back(n / i);
      }
    }
  }
  return ret;
}

int main() {
  int64_t n;
  cin >> n;
  vector<int64_t> ret = divisors(n);
  int64_t init = 0;
  cout << accumulate(ret.begin(), ret.end(), init) << '\n';
  return 0;
}