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 ITP1_3_C
{
    class Program
    {
        static void Main(string[] args)
        {
            var list = new List<List<int>>();
            string input;
            while ((input = Console.ReadLine()) != "0 0")
                list.Add(input.Split(' ').Select(x => Convert.ToInt32(x)).ToList());
            foreach (var l in list)
            {
                l.Sort();
                string[] str = l.Select(x => x.ToString()).ToArray();
                Console.WriteLine(string.Join(" ", str));
            }
        }      
    }
}