Finite state machines: flip-flop
	JK flip-flop:
						q	J	K	q+	z
		State: 1 bit (q)				0	0	0	0	0		hold
		Input: 2 bits (JK)				0	0	1	0	0		reset
		Output: current state (z)				0	1	0	1	0		set
						0	1	1	1	0		toggle
						1	0	0	1	1		hold
						1	0	1	0	1		reset
						1	1	0	1	1		set
						1	1	1	0	1		toggle
	Input is 2 bits, so there are 4 outgoing arcs from each state, but 2 pairs are equivalent
	This can be implemented with either a T or D flip-flop