while True:

    x,y = list(map(int,input().split()))

    if (x,y) ==(0,0): break

    if x < y:

        print((x,y))

    else:

        print((y,x))

while True:

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

    if a == 0 and  b==0:

        break

    if a > b:

        print((b,a))

    else:

        print((a,b))

while True:
    x, y = list(map(int, input().split()))
    if (x, y) == (0, 0):
        break
    if x < y:
        print((x, y))
    else:
        print((y, x))

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

-    x, y = list(map(int, input().split())) -    if (x, y) == (0, 0): +    a, b = list(map(int, input().split())) +    if a == 0 and b == 0: -    if x < y: -        print((x, y)) +    if a > b: +        print((b, a)) -        print((y, x)) +        print((a, b))