using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<String> trees = new List<String>{ "Oak", "Birch", "Beech", "Elm", "Hazel", "Maple" };

        //The below select stament transforms each element in tree into its first character.

        IEnumerable<String> initials = trees.Select(tree => tree.Substring(0, 1));

        foreach (String initial in initials) {

            System.Console.WriteLine(initial);

        }

    }

}