#include <iostream>
#include <algorithm>

using namespace std;

typedef long long ll;

int main()
{
	ll n, m;
	cin >> n >> m;

	ll maxN = 2 * n;
	ll maxM = 3 * m;

	for (int i = 2; i <= min(maxN, maxM); i += 2)
	{
		if (i % 3 == 0)
		{
			if (maxN <= maxM) maxN += 2;
			else maxM += 3;
		}
	}

	ll maxTower = max(maxN, maxM);
	cout << maxTower;
}