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: Wrong Answer)

using System;
namespace csharptest
{
    class Program
    {
        void swap(object x, object y)
        {
            object t;
            t = y;
            y = x;
            x = t;
        }
        static void Main(string[] args)
        {
            int[,] a = new int[1000, 2];
            int c=0;
            string[] str = Console.ReadLine().Split(' ');
            a[0, 0] = int.Parse(str[0]);
            a[0, 1] = int.Parse(str[1]);
            while (a[c, 0] != 0 && a[c, 1] != 0)
            {
                if (a[c, 0] > a[c, 1])
                {
                    int t;
                    t = a[c, 0];
                    a[c, 0] = a[c, 1];
                    a[c, 1] = t;
                }
                c++;
                str = Console.ReadLine().Split(' ');
                a[c, 0] = int.Parse(str[0]);
                a[c, 1] = int.Parse(str[1]);
            }
            for (int n = 0; n < c; n++)
            {
                Console.WriteLine(a[n, 0] + " " + a[n, 1]);
            }
        }
    }
}