#include <bits/stdc++.h>
using namespace std;
using i64 = int64_t;
using vi = vector<i64>;
using vvi = vector<vi>;

int main() {
    i64 n;
    i64 ret = 0;
    cin >> n;
    for (i64 i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ret += i;
            if (i != n / i) {
                ret += n / i;
            }
        }
    }
    cout << ret << endl;
}