T = int(input())
for i in range(T):
	N,M = map(int,input().split())
	if(N % 4 >= 2):
		N -= 2
		M += 4
	A = N // 4
	B = M // 2
	if(A <= B):
		print(A * 3)
	else:
		K = (A - B - 1) // 5 + 1
		A -= K
		B += 4 * K
		print(min(A,B) * 3)