/* -*- coding: utf-8 -*-
 *
 * 888.cc:  No.888 約数の総和 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

typedef long long ll;

/* global variables */

/* subroutines */

/* main */

int main() {
  ll n;
  scanf("%lld", &n);

  ll sum = 0;
  for (ll p = 1; p * p <= n; p++)
    if (n % p == 0) {
      sum += p;
      ll q = n / p;
      if (p != q) sum += q;
    }

  printf("%lld\n", sum);
  return 0;
}