import sys



n = sys.stdin.readlines()

for i in n:

    a = [int(x) for x in i.split()]

    if a[0] == 0 and a[1] == 0:

        break

    print((*sorted(a)))
import sys



n = sys.stdin.readlines()

for i in n:

    a, b = [int(x) for x in i.split()]

    if a == 0 and b == 0:

        break

    if a < b:

        print((a, b))

    else:

        print((b, a))
import sys

n = sys.stdin.readlines()
for i in n:
    a = [int(x) for x in i.split()]
    if a[0] == 0 and a[1] == 0:
        break
    print((*sorted(a)))

import sys

n = sys.stdin.readlines()
for i in n:
    a, b = [int(x) for x in i.split()]
    if a == 0 and b == 0:
        break
    if a < b:
        print((a, b))
    else:
        print((b, a))

-    a = [int(x) for x in i.split()] -    if a[0] == 0 and a[1] == 0: +    a, b = [int(x) for x in i.split()] +    if a == 0 and b == 0: -    print((*sorted(a))) +    if a < b: +        print((a, b)) +    else: +        print((b, a))