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)

lines = []
while line = gets
  lines << line.chomp.split(' ').map(&:to_i)
end
lines.delete_at(lines.length - 1)

lines.each do |line|
  if line[0] <= line[1]
    puts "#{line[0]} #{line[1]}"
  else
    puts "#{line[1]} #{line[0]}"
  end
end