prime=set([])

def factorization(n):
    res=[0 for i in range(n+1)]
    for i in range(2,n+1):
        if not res[i]:
            prime.add(i)
            for j in range(1,(n)//i+1):
                res[i*j]+=1

factorization(5*10**6)

import sys

input=sys.stdin.buffer.readline
for _ in range(int(input())):
    a,p=map(int,input().split())
    if p in prime:
        if a==0:
            print(0)
        else:
            print(1)
    else:
        print(-1)