func main()
	const n: int :: 5000000
	var primes: []int :: #[n]int
	do primes[0] :: 2
	var primesNum: int :: 1
	for i(3, n, 2)
		for j(0, primesNum - 1)
			var prime: int :: primes[j]
			if(prime ^ 2 > i)
				break j
			end if
			if(i % prime = 0)
				skip i
			end if
		end for
		do primes[primesNum] :: i
		do primesNum :+ 1
	end for
	var primeDict: dict<int, bool> :: #dict<int, bool>
	for i(0, primesNum - 1)
		do primeDict.add(primes[i], true)
	end for
	
	var t: int :: cui@inputInt()
	for(1, t)
		do cui@inputInt()
		var p: int :: cui@inputInt()
		
		var ans: int :: primeDict.get(p, &) ?(1, -1)
		do cui@print("\{ans}\n")
	end for
end func