import java.util.*;
//
// This uses a HashSet rather than ArrayList
// Spot the differences!
//

public class TestHS {      
    
    public static void main(String[] args) {
	
	String commands = "HashSet Tester (version 299792458) \n" +
	                  "add (+), remove (-), contains (?), clear, size, show, help, quit (q)";
	
	System.out.println(commands);
	Scanner sc = new Scanner(System.in);
	
	System.out.print("> ");
	String command = sc.next();
	HashSet<String> S = new HashSet<String>();
	
	while (!command.equals("quit") && !command.equals("q")){

	    if (command.equals("add") || command.equals("+")){
		System.out.print(">> ");
		S.add(sc.next());
	    }

	    if (command.equals("remove") || command.equals("-")){
		System.out.print(">> ");
		S.remove(sc.next());
	    }
	    
	    if (command.equals("contains") || command.equals("?")){
		System.out.print(">> ");
		System.out.println(S.contains(sc.next()));
	    }

	    if (command.equals("clear")) S.clear();

	    if (command.equals("size")) System.out.println(S.size());

	    if (command.equals("show")) System.out.println(S);
	    
	    if (command.equals("help")) System.out.println(commands);

	    System.out.println(S);

	    System.out.print("> ");
	    command = sc.next();
	}
    }
}