from sys import stdin


def div(p, wari):
    return (p + wari - 1) // wari


def r(p, wari):
    return wari * div(p, wari) - p

def main():
    t = int(stdin.readline())
    for _ in range(t):
        n, m = map(int, stdin.readline().split())
        charge = div(n, 4)
        rest = r(n, 4)
        m -= rest

        no_charge = min(div(m, 4), charge)
        m -= no_charge * 4

        no_charge += div(m, 8)

        print(max(charge, no_charge))
    return


if __name__ == "__main__":
    main()