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)

numbers_x = []
numbers_y = []
while True:
  x,y=map(int, input().split())
  if x==0 and y==0:
    break
  if x > y:
    x,y = y,x
  numbers_x.append(x)
  numbers_y.append(y)

for i in range(len(numbers_x)):
  print(numbers_x[i],numbers_y[i])