What's the right way to design my interface when I have operations that aren't supported by all implementers?

I have an Interface and two Classes which are implementing the Interface.

public interface MyInterface {
    public void firstMethod();  
    public int secondMethod();
}

public class MyClass1 implements MyInterface  {
    public void firstMethod() {}
}

public class MyClass2 implements MyInterface  {
    public void firstMethod() {}
    public int secondMethod() {}
}

The class MyClass1 is telling me to Add unimplemented methods, because the secondMethod is not implemented, OK I will do that. But the problem is that I don't need this method in MyClass1.

In your opinion what is the best thing to do?

1. Add the unimplemented method with something like return 0
2. There is another way to fix this if I don't want to implement it.