#include <bits/stdc++.h>
using namespace std;

template<class T>T DivSum(T n) {
	T i = 1, ret = 0;
	for (; i * i < n; ++i)if (n % i == 0)ret += i + n / i;
	return ret + i * (i * i == n);
}

int main(){
    long long n;
    cin >> n;
    cout << DivSum(n) << endl;
}