import sys

data = list(map(int, sys.stdin.read().split()))

T = data[0]
index = 1

for _ in range(T):
    N = data[index]
    M = data[index + 1]
    index += 2
    make = min(N // 4, M // 2)
    N -= make * 4
    M -= make * 2
    make += (N // 10) * 2
    N %= 10
    if N >= 6:
        make += 1

    print(make * 3)