using System;
using System.Linq;
public class Test
{
	public static void Main()
	{
    	var arr1 = new[] { "A", "B", "C", "D", "E"};
      	var result = (from i1 in arr1
             from i2 in arr1.Where( i=> i[0]>i1[0])
            select i1+i2).ToArray();
			
		foreach(var str in result)
		  Console.WriteLine(str);
	}
}