class User {
	private String name;
	
	public User( String name ) {
		this.name = name;
	}

	public boolean equals( Object obj ) {
		User user = (User) obj;
		return user.name.equals( name );
	}

	public String toString() {
		return name;
	}
}

class Foo {
	public static void main(String...arguments) {  //1
		User user1 = new User( "John" ); 
		User user2 = new User( "Bill" ); 
		User user3 = new User( "John" ); 

		Set<User> userSet = new HashSet<User>();
		userSet.add( user1 );
		userSet.add( user2 );
		userSet.add( user3 );  //2

		System.out.println( "Count of users: " + userSet.size() );  //3
	}
}