#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;

int main() {
    long long N; cin >> N;
    long long ans =0;
    for(long long i = 1; i <= sqrt(N); i++) {
        if(N % i == 0) {
            ans += i;
            if(N / i != i) {
                ans += N / i;
            }
        }
    }
    cout << ans << endl;
}