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
    Z = 0
    if N == 0:
        Z = 0
    elif M == 0:
        while N >= 2:
            N = N - 2
            M = M + 4
        if M >= 2:
            N = N - 4
            M = M - 2
            Z = Z + 1
    else:
        S1 = (N // 4)
        S2 = (M // 2) 
        if S1 > S2:
            N = N - 4 * S2
            M = M - 2 * S2  
            Z = Z + S2 * 3
            if N >= 4:
                if M >= 2:
                    N = N - 4
                    M = M - 2
                    Z = Z + 3
                else:
                    while N >= 2:
                        N = N - 2
                        M = M + 4
                    if M >= 2:
                        N = N - 4
                        M = M - 2
                        Z = Z + 1
        else:
            Z = (N // 4) * 3
    print(Z)