#include <iostream>
int main(){
	int n, ans = 1000000000; std::cin >> n;
	for(int a = 1; a*a <= n; ++a)
		for(int b = 1, c=(n+a*b-1)/(a*b); b<=a; ++b, c=(n+a*b-1)/(a*b))
			ans = std::min(ans, 2*(a*b+b*c+c*a));
	std::cout << ans << "\n";
}