using System;
using System.Linq;

public class Test
{
	public static void Main()
	{
		char[] chrs = { 'A', 'B', 'C'};
        char[] chrs2 = { 'X', 'Y', 'Z' };
        var pairs = chrs.SelectMany(ch1 => chrs2, (ch1, ch2) => ch1 + " " + ch2);
        Console.WriteLine("For ABC and XYZ: ");
        foreach (var p in pairs)
            Console.WriteLine(p);
        Console.WriteLine();

        Console.WriteLine("For D and W: ");
        chrs = new char[] { 'D' };
        chrs2 = new char[] { 'W' };
        foreach (var p in pairs)
            Console.WriteLine(p);
	}
}