def divisors(n: int) -> list[int]:
    """n の約数を求める"""
    s = set()
    p = 1
    while p * p <= n:
        if n % p == 0:
            s.add(p)
            s.add(n // p)
        p += 1
    return sorted(s)


def solve():
    N, K = map(int, input().split())

    for x in reversed(range(max(1, N-281), N+1)):
        if x <= K: break
        ds = divisors(x)
        ok = True
        for d in ds:
            a = d
            b = x // d
            if a <= K and b <= K:
                ok = False
                break

        if ok:
            return x
        elif len(ds) == 2:  # priem
            break

    return -1


T = int(input())
for _ in range(T):
    ans = solve()
    print(ans)