So D stands for dye, c stands for cyclohexyl, and second, C stands for carbal diamide. And the blocking agent that we're going to use that essentially attaches and blocks the nitrogen on the amino group of that amino acid, es, tbock and B stands for butyl O stands for oxy. MC stands for Carbonal. So we have DCC and Tbock that must be used in this method to basically prevent different types of competing reactions and competing products from actually forming. So in step number one, what we want to do is we want to prepare these amino acids. So by reacting our amino acids, so this molecule here with DCC, we're forming this attachment and that activates this carbon.