n = input()
for i in xrange(n):
	x, y = map(int, raw_input().split(' '))
	z = x - y
	if(z % 2 == 0 and z >= 0):
		p = z / 2
		q = y
		a = 0
		b = 0
		f = True
		for i in xrange(64):
			if((p & (1 << i)) and not (q & (1 << i))):
				a |= (1 << i);
				b |= (1 << i)
			elif(not (p & (1 << i)) and (q & (1 << i))):
				b |= (1 << i)
			elif(not (p & (1 << i)) and (not q & (1 << i))):
				pass
			else:
				print -1
				f = False
				break
		if(f):
			print a, b
			assert(a + b == x and a ^ b == y)
	else:
		print -1

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

NQo0IDIKMyA0CjMgMwo1IDIKOSA1Cg==

5
4 2
3 4
3 3
5 2
9 5