#include "bits/stdc++.h"

using namespace std;

void solve(void)
{
	long h, w;
	cin >> h >> w;
	cout << (w + h - 1) / w * 2 * h << endl;
}

int main()
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}