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;

namespace _1_3_A {
    class Program {
        static void Main(string[] args) {
            var list = new List<KeyValuePair<int, int>>();
            var pair = new KeyValuePair<int, int>();
            while (true) {
                var input = Console.ReadLine();
                var array = input.Split(' ').Select(x => int.Parse(x)).ToArray();

                if (array[0] == 0 && array[1] == 0)
                    break;

                if (array[0] > array[1]) {
                    var temp = array[0];
                    array[0] = array[1];
                    array[1] = temp;
                }

                list.Add(new KeyValuePair<int, int>(array[0], array[1]));
            }
            list.ForEach(x => Console.WriteLine($"{x.Key} {x.Value}"));
        }
    }
}