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 Python3 (judge verdict: Wrong Answer)

import sys
for i in sys.stdin.readlines() :
    l = i.split()
    a = l[0]
    b = l[1]
    if a == 0 and b == 0 :
        break
    elif a > b :
        print(b,a)
    else :
        print(a,b)