import java.util.HashSet;
import java.util.Set;

/**
   This program prints hash codes of countries.
*/
public class HashCodePrinter
{
   public static void main(String[] args)
   {
      Country country1 = new Country("Belgium", 30510);
      Country country2 = new Country("Thailand", 514000);
      Country country3 = new Country("Belgium", 30510);

      System.out.println("hash code of country1=" + country1.hashCode());
      System.out.println("hash code of country2=" + country2.hashCode());
      System.out.println("hash code of country3=" + country3.hashCode());

      // Add the countries to the hash set. 

      Set<Country> countries = new HashSet<>();
      countries.add(country1);
      countries.add(country2);
      countries.add(country3);

      // Print the set. Note that the set has two elements.

      System.out.println(countries);
   }
}