using System;

using System.Linq;

using System.Collections.Generic;

 public class Program

    {

​

        public static void Main(string[] args)

        {

​

            var words = new List<string> { "sky", "rock", "forest", "new",

    "falcon", "jewelry", "small", "eagle", "blue", "gray" };

​

            var res = from word in words

                      where word.StartsWith("f") || word.StartsWith("s")

                      select word;

​

            foreach (var word in res)

            {

​

                Console.WriteLine(word);

​

            }

​

            Console.ReadLine();

        }

    }

​