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;
using System.Text;
using System.Threading.Tasks;

namespace ITP1
{
    class ITP1_3_C
    {
        static void Main(string[] args)
        {
            while (true)
            {
                List<int> dataSet = Console.ReadLine().Split().Select(int.Parse).ToList();
                if ((dataSet[0] == 0) && (dataSet[1] == 0))
                {
                    break;
                }
                else
                {
                    dataSet.Sort();
                    Console.WriteLine($"{dataSet[0]} {dataSet[1]}");
                }
            }
        }
    }
}