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;
public class Hello{
    public static void Main(){
        var list = new List<string>();
        
        while(true){
            var a = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            Array.Sort(a);
            if(a[0] == 0 && a[1] == 0){
                break;
            }else{
                list.Add($"{a[0]} {a[1]}");
            }
        }
        
        foreach(var i in list){
            Console.WriteLine(i);
        }
    }
}