def divisor(n): 
    i = 1
    table = []
    while i * i <= n:
        if n%i == 0:
            table.append(n//i)
        i += 1
    return min(table)

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

    ans = -1
    for i in range(N,K,-1):
        if(divisor(i) > K):
            ans = i
            break
    print(ans)