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