Construct a block diagram and an ASMD chart for digital system thatcounts the number of people in a room. The one door through whichpeople enter the room has photocell that changes a signal x from 1to 0 when the light is interrupted. They leave the room from asecond door with a similar phot0cell that changes a signal y from 1to 0 when the light is interrupted. The datapath circuit consistsof an up-down counter with a display that shows how many people are in the room.