An elevator system has two states: moving $($M$)$ and stopped $($S$).$ When an elevator is moving, it can be going up $($Mu$)$ or down $($Md$).$ It also has two inputs: button pressed to move up $($U$)$ and button pressed to move down $($D$).$ Every time the button is pressed the elevator moves up or down one level and stops. Assume there are infinite levels. Design an FSM for this elevator system. Draw the state table and the state diagram.