T = int(input())   

for _ in range(T):
    N, M = map(int, input().split())

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