using System;

public class Program

{

    public static void Main()

    {

        List<string> onTime = new List<string>() { "Paulius", "Saulius", "Andrius", "Tomas" };

            List<string> late = new List<string>() { "Rokas", "Mantas", "Jonas", "Algis" };

​

            late.ForEach(item => onTime.Add(item));

            Console.WriteLine(String.Join(",", onTime));

​

            onTime.Sort();

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

    }

}