Elwood the Electronic Watchdog

Elwood is a dog who has a very simple behavior. He barks whenever the doorbell rings. Also, he will bark if the phone rings provided that his human, Elmer, is snoring.

Let's design a circuit for Elwood. His input sensors (bits) are:

	A value of 1 indicates ringing. A value of 0 indicates no ringing.
	A value of 1 indicates ringing. A value of 0 indicates no ringing.
	A value of 1 indicates snoring. A value of 0 indicates no snoring.

Draw the circuit which demonstrates Elwood's barking behavior: (Note that some people like to draw circuits so that the bit values flow up the page with the output on top, others like the values to flow down the page with the output on the bottom, and still others like the values to go from left to right. Do it whatever way you like.)