Kara wants to lay down a chessboard pattern. There are two different ways of generating such a pattern. Can you imagine what they might be?
Hint: Choose a world size so that your program becomes as simple as possible. Depending on your algorithm, the requirements regarding the world size are different. Does it help your program if the world width and height are even or odd? Or does it help to know that width and height are equal?
Additional question: What size can the smallest world be so that your program still works?