#include <iostream>
#include<cstdlib>
#include<vector>
#include<algorithm>
using namespace std;

int main()
{
	long long n; cin >> n;
	if (!(n % 2))n /= 2;

	long long sum = 1;
	for (long long i = 2; i*i <= n; i++){
		if (!(n%i)){
			while (!(n%i))n /= i;
			sum += i;
		}
	}
	if(n!=1)sum += n;

	cout << sum << endl;

	return 0;
}