T = int(input())   
Z = 0
for _ in range(T):
    N, M = map(int, input().split())

#N木材 M木棒 Z栅栏

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:
    if N > M:
        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)