// yukicoder No.888
#include <bits/stdc++.h>
#define ll long long

using namespace std;

int main()
{
    ll n;
    cin >> n;

    ll ans = 0;
    ll lim = sqrt(n);



    for (int i = 1; i <= lim; ++i) {
        if (n % i == 0) {
            ans += i;
            if(i != n / i) ans += n / i;
            else continue;
        }
        else continue;
    }

    cout<< ans << "\n";

    return 0;
}