Problem:
Swapping Two Numbers

Write a program which reads two integers x and y, and prints them in ascending order.

Input

The input consists of multiple datasets. Each dataset consists of two integers x and y separated by a single space.

The input ends with two 0 (when both x and y are zero). Your program should not process for these terminal symbols.

Output

For each dataset, print x and y in ascending order in a line. Put a single space between x and y.

Constraints

0 ≤ x, y ≤ 10000

the number of datasets ≤ 3000

Sample Input

3 2
2 2
5 3
0 0

Sample Output

2 3
2 2
3 5

Solution in Python (judge verdict: Wrong Answer)

listx = []
listy = []
while True:
    x,y = map(int,raw_input().split())
    if x==0 and y==0:
        break
    listx.append(x)
    listy.append(y)

listx.sort()
listy.sort()

for i in range(len(listx)):
    print '%s %s'% (listx[i],listy[i])