#include <bits/stdc++.h>
using namespace std;
int main() {
    long long n;
    cin >> n;
    long long sum = 0;
    for (long long i=1;i*i<=n;++i){
        if(n%i==0){
            sum+=i;
            if (n/i!=i){
                sum+=n/i;
            }
        }
    }
    cout<<sum<<endl;
    return 0;
}