import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test{
	public static void main(String[] args) {

		List<Foo> myFooList = new ArrayList<Foo>();
		myFooList.add(new Foo("C"));
		myFooList.add(new Foo("A"));
		myFooList.add(new Foo("D"));

		Collections.sort(myFooList); 
		System.out.print(myFooList.get(0).code);

	}
}

class Foo implements Comparable<Foo> {
	String code;

	Foo(String c) {
		code = c;
	}

	int compareTo(Foo f) {
		return this.code.compareTo(f.code);
	}

}
                                

A  A

B  C

C  D

D  no output is printed

E  compilation error

F  exception thrown at run time