#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#define popcount __builtin_popcount
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

int main()
{
	ll n; cin>>n;
	ll ans=0;
	for(ll i=1; i*i<=n; i++){
		if(n%i==0){
			ans+=i;
			if(i*i<n) ans+=n/i;
		}
	}
	cout<<ans<<endl;
	return 0;
}