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 Ruby (judge verdict: Accepted)

attrs = Array.new
while line = $stdin.gets
    attrs << line.chomp.split.map{|v| v.to_i }
end

for i in 0...(attrs.length) do
  break if attrs[i] == [0, 0]
  a, b = attrs[i].sort
  puts "#{a} #{b}"
end