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;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                var xy = Console.ReadLine().Split().Select(int.Parse).ToArray();
                var x = xy[0];
                var y = xy[1];
                if (x == 0)
                {
                    if (y == 0)
                        break;
                }
                if (x > y)
                {
                    var X = x;
                    x = y;
                    y = X;
                }
                Console.WriteLine("{0} {1}",x,y);
            }
        }
    }
}