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

signed main() {
  int N;
  cin >> N;
  
  int ans = 0;
  for( int i = 1; i <= N/2+1; i++ ){
    if( N % i == 0 ){
      ans += i;
    }
  }
  cout << ans + N << endl;
}