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: Accepted)

from sys import stdin

while True:
    x, y = [int(x) for x in stdin.readline().rstrip().split()]
    if x == 0 and y == 0:
        break
    else:
        if x > y:
            print(y, x)
        else:
            print(x, y)