def seachPrimeNum(N):
    max = int(N**0.5)
    seachList = [i for i in range(2,N+1)]
    primeNum = []
    while seachList[0] <= max:
        primeNum.append(seachList[0])
        tmp = seachList[0]
        seachList = [i for i in seachList if i % tmp != 0]
    primeNum.extend(seachList)
    return primeNum

PL = set(seachPrimeNum(5*10**5))

for _ in range(int(input())):
    a,p = map(int,input().split())
    if p not in PL:
        print(-1)
    elif a % p == 0:
        print(0)
    else:
        print(1)