using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var people = new List<Person>()

        {

            new Person("Bill", "Smith", 41),

            new Person("Sarah", "Jones", 22),

            new Person("Stacy","Baker", 21),

            new Person("Vivianne","Dexter", 19 ),

            new Person("Bob","Smith", 49 ),

            new Person("Brett","Baker", 51 ),

            new Person("Mark","Parker", 19),

            new Person("Alice","Thompson", 18),

            new Person("Evelyn","Thompson", 58 ),

            new Person("Mort","Martin", 58),

            new Person("Eugene","deLauter", 84 ),

            new Person("Gail","Dawson", 19 ),

        };

        //write linq statement for people with last name that starts with the letter D

        var people1 = people.Count(n => n.LastName.ToUpper().First() == 'D');

​

        Console.WriteLine("Number of people who's last name starts with the letter D " + people1);

        Console.WriteLine();

        //Write linq statement for first Person Older Than 40 In Descending Alphabetical Order By First Name

        Person person2 = people.OrderBy(n => n.FirstName).Where(n => n.Age >40).First();

        Console.WriteLine("First Person Older Than 40 in Descending Order by First Name " + person2.ToString());

    }

    public class Person

    {

        public Person(string firstName, string lastName, int age)

        {

            FirstName = firstName;

            LastName = lastName;

            Age = age;

        }

        public string FirstName {get;set;}

        public string LastName {get;set;}

        public int Age {get;set;}

        public override string ToString()  

        {  

            return this.FirstName + " " + this.LastName + " " +this.Age;  

        }

    }

}