And once again, after cycle two completes, we essentially have four copies. So we begin with a single copy. After one cycle, we have two copies. After two cycles, we have four copies. After three cycles, we're going to have eight copies. And the general equation that describes how many copies of DNA we can theoretically produce after N number of cycles is two to the power of N. So this gives us the number of copies of DNA after N number of cycles.