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

int main()
{
	long long N;
	cin >> N;

	vector<long long> v;
	for( long long i = 1; i * i <= N; i++ ) {
		if( N % i == 0 ) {
			v.push_back( i );
			if( N / i != i ) v.push_back( N / i );
		}
	}
	long long ans = 0;
	for( int i = 0; i < v.size(); i++ ) {
		ans += v[i];
	}

	cout << ans << endl;
}