#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define all(a) (a).begin(), (a).end()
const int maxn = 1e6+1;
int main()
{
	ll n, sum = 0;
	cin>>n;
	for(int i=1;i<=sqrt(n);++i){
		if(n%i==0){
			sum += i;
			if(n/i != i) sum += n/i;
		}
	}
	cout<<sum;
	return 0;

}
/*---------------END---------------*/