using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var roster = GetThreadRoster(1000000);  

        Stopwatch timer1 = Stopwatch.StartNew();

        var t1 = Preet(roster);

        Console.WriteLine("Preet: "+ t1.Count() + " : " + timer1.ElapsedMilliseconds);

        Stopwatch timer2 = Stopwatch.StartNew();

        var t2 = Gaurav(roster);

        Console.WriteLine("Gaurav: "+ t2.Count() + " : " + timer2.ElapsedMilliseconds);

    }

    public static IEnumerable<int> GetThreadRoster(int length)

    {

        var list = new List<int>();

        for(int i=1; i<=length; i++)

        {

            list.Add(i);

        }

        return list;

    }

    public static IEnumerable<ReplyActivity> Gaurav(IEnumerable<int> threadRoster)

    {

        var replyActivities = new List<ReplyActivity>();

        threadRoster.Where(rosterMember => rosterMember%3 != 0).ToList().

                    ForEach(rosterMember =>

                    {

                        replyActivities.Add(new ReplyActivity(rosterMember));

                    });     

        return replyActivities;

    }

    public static IEnumerable<ReplyActivity> Preet(IEnumerable<int> threadRoster)

    {

        var replyActivities = threadRoster

                .Where(rosterMember => rosterMember%3 != 0)

                .Select(rosterMember => new ReplyActivity(rosterMember));

        return replyActivities;

    }

    public class ReplyActivity

    {

        private int temp;

        public ReplyActivity(int t)

        {

            temp = t;

        }

    }

}