#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n;
    cin >> n;
    ll ans = 0;
    for (ll i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ans += i;
            if (i != n / i) ans += n / i;
        }
    }
    cout << ans << endl;
    return 0;
}