import java.util.HashMap;

​

public class Main {

  public static void main(String[] args) {

    HashMap<String, String> capitalCities = new HashMap<String, String>();

    capitalCities.put("England", "London");

    capitalCities.put("Germany", "Berlin");

    capitalCities.put("Norway", "Oslo");

    capitalCities.put("USA", "Washington DC");

    for (String i : capitalCities.keySet()) {

      System.out.println(i);

    }

  }

}

​