import java.util.*;

class Demo {

    static void printMap(Map map) {
	Set keys = map.keySet();
	Iterator i = keys.iterator();
	while (i.hasNext()) {
	    Object key = i.next();
	    Object value = map.get(key);
	    System.out.println("key: " + key + " value: " + value);
	}
    }

    public static void main (String[] args) {

	Map ages = new HashMap();

	ages.put("Mark", new Integer(16));
	ages.put("John", new Integer(15));
	ages.put("Mary", new Integer(17));
	ages.put("Jane", new Integer(16));
	System.out.println(ages);

	ages.remove("Mary");
	System.out.println(ages);

	System.out.println(ages.get("John"));
	System.out.println(ages.get("Mary"));

	printMap(ages);

	Map log2 = new TreeMap();

	log2.put(new Integer(2), new Integer(1));
	log2.put(new Integer(64), new Integer(6));
	log2.put(new Integer(16), new Integer(4));
	log2.put(new Integer(32), new Integer(5));
	log2.put(new Integer(8), new Integer(3));
	System.out.println(log2);

	log2.remove(new Integer(16));
	System.out.println(log2);

	System.out.println(log2.get(new Integer(4)));
	System.out.println(log2.get(new Integer(64)));

	printMap(log2);
    }
}