import java.util.TreeMap;
import java.util.Scanner; 
import java.util.*;

/**
 * Created by leon on 1/23/18.
 */
public class PhoneBook {
   // private String name;
   // private String phoneNumber;
    private Map<String, String> phoneBook;
    
public PhoneBook() {
    // Create a TreeMap
    phoneBook = new TreeMap<>();
    
    
   
}

public  void addListings(String name, String phoneNumber) {
    phoneBook.put(name, phoneNumber);
  
}

public int size() {
    return phoneBook.size();
}

public void removeListings(String name, String phoneNumber) {
    phoneBook.remove(name, phoneNumber);
}


public void lookupByKey(String name, String phoneNumber) {
     System.out.println(phoneBook.get(name));
}

public void lookupByValue(String name, String phoneNumber) {
    System.out.println(phoneBook.get(phoneNumber));
}

public void display() {
    System.out.println(phoneBook);
}
}