using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var personNames = new[] 

    {

        "Foo", "Bar", "Fizz", "Buzz"

    };

    var namesStartingWithF = personNames.Where(p => p.StartsWith("F"));

    Console.WriteLine(string.Join(",", namesStartingWithF));

    }

}