while 1:

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

	if a == b == 0:

		break

	elif a < b:

		print("%s %s" % (a,b))

	else:

		print("%s %s" % (b,a))
while 1:

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

	if a == 0 and b == 0:

		break

	elif a < b:

		print(a, b)

	else:

		print(b, a)
while 1:
    a, b = list(map(int, input().split()))
    if a == b == 0:
        break
    elif a < b:
        print("%s %s" % (a, b))
    else:
        print("%s %s" % (b, a))

while 1:
    a, b = list(map(int, input().split()))
    if a == 0 and b == 0:
        break
    elif a < b:
        print(a, b)
    else:
        print(b, a)

-    if a == b == 0: +    if a == 0 and b == 0: -        print("%s %s" % (a, b)) +        print(a, b) -        print("%s %s" % (b, a)) +        print(b, a)