using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections.ObjectModel;

​

public class Program

{

    public static void Main()

    {

        Dictionary<string, City> city = new Dictionary<string, City>();

            city.Add("St. John's", new City(100645,"Newfoundland and Labrador"));

            city.Add("HALIFAX", new City(372680,"NOVA SCOTIA"));

            city.Add("FREDERICTON", new City(34000,"NEW BRUNSWICK"));

            city.Add("CHARLOTTETOWN", new City(34562,"PRINCE EDWARD ISLAND"));

            city.Add("QUÉBEC", new City(8180000,"QUEBEC"));

            city.Add("TORONTO", new City(2791140,"Ontario"));

            city.Add("WINNIPEG", new City(633450,"MANITOBA"));

            city.Add("REGINA", new City(179245,"SASKATCHEWAN"));

            city.Add("EDMONTON", new City(730375,"ALBERTA"));

            city.Add("Victoria", new City(78055,"BC"));

            city.Add("IQALUIT",new City(6699,"NUNAVUT"));

            city.Add("YELLOWKNIFE",new City(19234,"NORTHWEST TERRITORIES"));

            city.Add("WHITEHORSE",new City(27889,"YUKON"));

​

            foreach(var c in city)

            {

                Console.WriteLine("{0} is a city in {1}", c.Key,c.Value.province); 

            }

​

            Console.WriteLine("--------------------------------------------------");

​

            var set = new HashSet<string>();

            set.Add("MEXICO CITY");

            set.Add("NEW YORK CITY");

            set.Add("LOS ANGELES");

            set.Add("TORONTO");

            set.Add("CHICAGO");

            set.Add("HOUSTON");

            set.Add("HAVANA");

            set.Add("ECATEPEC DE MORELOS");

            set.Add("MONTREAL");

            set.Add("PHILADELPHIA");

​

            set.IntersectWith(city.Keys);

            foreach(var I in set)

            {

                Console.WriteLine("{0} is in Canada and also in the top 10 largest cities in North America.", I);

            }

​

            Console.ReadLine();

        }

    }

​

 public class City

    {

        public int population { get; set; }

​

        public string province { get; set; }

​

​

        public City(int population, string province)

        {

            this.population = population;

            this.province = province;

        }

​

    }

​