while True:

	a, b = sorted(map(int, input().split()))

	if (a == 0) & (b == 0): break

	print((a, b))
while True:

	a, b = list(map(int, input().split()))

	if a == 0 and b == 0:

		break

	if a < b:

		print((a, b))

	else:

		print((b, a))

while True:
    a, b = sorted(map(int, input().split()))
    if (a == 0) & (b == 0):
        break
    print((a, b))

while True:
    a, b = list(map(int, input().split()))
    if a == 0 and b == 0:
        break
    if a < b:
        print((a, b))
    else:
        print((b, a))

-    a, b = sorted(map(int, input().split())) -    if (a == 0) & (b == 0): +    a, b = list(map(int, input().split())) +    if a == 0 and b == 0: -    print((a, b)) +    if a < b: +        print((a, b)) +    else: +        print((b, a))