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

ll sus(ll N) 
{
    ll sum = 0;
    for (ll i = 1; i * i <= N; ++i) 
	{
        if (N % i == 0) 
		{
            sum += i;
            if (i != N / i) 
                sum += N / i; 
        }
    }
    return sum;
}

signed main() 
{
	cin.tie(nullptr) -> sync_with_stdio(false);
	cout.tie(nullptr);

	#ifdef BACHS 	
		freopen("baitap.inp", "r", stdin);
		freopen("baitap.out", "w", stdout);
	#endif
	
    ll N;
    cin >> N;
    cout << sus(N) << endl; 
    return 0;
}