while 1:

 n = eval(input())

 if n=='0 0':break

 print((*sorted(map(int,n.split()))))
a=[]

while 1:

 n=eval(input())

 if n=='0 0':break

 a.append(n)

for s in a:

 print((*sorted(map(int,s.split()))))
while 1:
    n = eval(input())
    if n == "0 0":
        break
    print((*sorted(map(int, n.split()))))

a = []
while 1:
    n = eval(input())
    if n == "0 0":
        break
    a.append(n)
for s in a:
    print((*sorted(map(int, s.split()))))

+a = [] -    print((*sorted(map(int, n.split())))) +    a.append(n) +for s in a: +    print((*sorted(map(int, s.split()))))