class Program
    {
        static void Main(string[] args)
        {
            string mid = ", middle part,";
            Func<string, string> lambda = param =>
                {
                    param += mid;
                    param += "and this was added to the string";
                    return param;
                };

            Console.WriteLine(lambda("Start of string"));
            Console.ReadKey();
        }
    }