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;

namespace ConsoleApp_ITP1_3_D
{
    class Program
    {
        static void Main(string[] args)
        {
            List<string> inputList = new List<string>();

            for (int i = 1; i <= 3000; i++)
            {
                string[] input = Console.ReadLine().Split(' ');
                var x = Int32.Parse(input[0]);
                var y = Int32.Parse(input[1]);

                if (x == 0 && y == 0)
                {
                    break;
                }
                else
                {
                    if (y < x)
                    {
                        var j = x;
                        x = y;
                        y = j;
                    }
                    var output = String.Concat(x, ' ', y);
                    inputList.Add(output);
                }
            }

            for (int i = 0; i < inputList.Count; i++)
            {
                Console.WriteLine(inputList[i]);
            }
        }
    }
}