#include <iostream>
#include <vector>
#include <string>
#include <utility>
#include <algorithm>
#include <climits>
#include <map>
#include <queue>
#include <cmath>

using namespace std;

using int64 = long long;


int main() {
    int64 n;
    cin >> n;

    int64 ans = 0;
    for (int i=1; i*i<=n; i++) {
        if (n%i==0) {
            ans += i;
            if (i!=n/i) ans += n/i;
        }
    }

    cout << ans << endl;
}