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.Linq;
using System.Text;

class Program
{
    static void Main()
    {
        string str;
        StringBuilder sb = new StringBuilder();
        while ((str = Console.ReadLine()) != "0 0") 
        {
            int[] arr = str.Split().Select(int.Parse).OrderBy(x => x).ToArray();
            sb.AppendLine($"{arr[0]} {arr[1]}");
        }
        Console.Write(sb);
    }
}