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 C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

namespace procon
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var list = new List<int[]>();
            while (true)
            {
                var tmp = Console.ReadLine().Split().Select(int.Parse).ToList();
                if (tmp[0] == 0 && tmp[1] == 0) break;

                list.Add(tmp.OrderBy(s => s).ToArray());
            }

            foreach (var item in list)
            {
                var str = string.Join(" ", item.Select(ss => ss.ToString()).ToArray<string>());
                Console.WriteLine(str);
            }
        }
    }
}