(a) [State Diagram] We will use a Moore machine to implement this vending machine. Before building a state diagram, let us define five states as follows: Based on this definition, complete the following state diagram: In doing so, assume that - Two inputs (N and D) are never asserted at the same time. - In the states that there is enough balance for coffee, i.e., in S15 and S20, none of the inputs is asserted