JAVA Read the width and height and print Letter D need help with my program?

The computer is telling you that you don't have a method called main, and it's right. This is not a program, it's just a class definition. How is the computer supposed to know what to do with it? You've told it there is a class called LetterD, and you've told it how to represent an instance of that class as a string. But you haven't told it to actually create any LetterDs, or to do anything with one, or to do anything at all.