​

using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

            // dictionary of Canadian capital cities

            var cities = new Dictionary<string, City>();

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

            cities.Add("Halifax", new City(372680, "Nova Scotia"));

            cities.Add("Fredricton", new City(34000, "New Brunsiwick"));

            cities.Add("Charlottetown", new City(34562, "Prince Edward Island"));

            cities.Add("Quebec", new City(8180000, "Quebec"));

            cities.Add("Toronto", new City(2503000, "Ontario"));

            cities.Add("Winnipeg", new City(633450, "Manitoba"));

            cities.Add("Regina", new City(176245, "Saskatchewan"));

            cities.Add("Edmonton", new City(730375, "Alberta"));

            cities.Add("Victoria", new City(78055, "British Columbia"));

            cities.Add("Iqaluit", new City(6699, "Nanavut"));

            cities.Add("Yellowknife", new City(19234, "Northwest Territories"));

            cities.Add("Whitehorse", new City(27889, "Yukon"));

​

            foreach (var city in cities)

            {

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

            }

            Console.WriteLine();

​

            // HashSet of the 10 largest cities in North America

            var northAmericanCities = new HashSet<string>();

            northAmericanCities.Add("Mexico City");

            northAmericanCities.Add("New York City");

            northAmericanCities.Add("Los Angeles");

            northAmericanCities.Add("Toronto");

            northAmericanCities.Add("Chicago");

            northAmericanCities.Add("Houston");

            northAmericanCities.Add("Havana");

            northAmericanCities.Add("Ecatepec de Morelos");

            northAmericanCities.Add("Montreal");

            northAmericanCities.Add("Phoenix");

​

            northAmericanCities.IntersectWith(cities.Keys);

            foreach (var city in northAmericanCities)

            { 

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

            }

            Console.WriteLine();

​

            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;

        }

    }

}