#include <bits/stdc++.h>
using namespace std;
long long n;
int main() 
{
    cin >> n;
    long long sum = 0;
    for (long long i = 1; i * i <= n; ++i) 
{
        if (n % i == 0) 
        {
            sum += i;
            if (i != n / i)
                sum += n / i;
        }
    }
    cout << sum << '\n';
    return 0;
}