def bisect(nm, a):
    ok = 0; ng = 10**10
    while abs(ok - ng) > 1:
        mid = (ok + ng) // 2
        if nm - a*mid >= 0: ok = mid
        else              : ng = mid
    return ok
##########################################################################
T = int(input())

for _ in range(T):

    N, M = map(int,input().split())

    k = bisect(N, 4)
    m = N - 4*k

    if M <= 4*k:
        if m > 0: print(k+1)
        else    : print(k)
    else:
        M -= 4*k
        M -= (8-m)
        k += 1

        l = bisect(M, 8)
        m = M - 8*l
        if m > 0: print(k+l+1)
        else    : print(k+l)