p 5.


xor


	A0 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C0
               |      |                 |
               |      +-----+           |
	       |            |           |
	B0 ----+--------X --+---- X ----+


 


	A1 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C1
               |      |                 |
               |      +-----+           |
	       |            |           |
	B1 ----+--------X --+---- X ----+


 


	A2 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C2
               |      |                 |
               |      +-----+           |
	       |            |           |
	B2 ----+--------X --+---- X ----+






	A3 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C3
               |      |                 |
               |      +-----+           |
	       |            |           |
	B3 ----+--------X --+---- X ----+



 


	A4 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C4
               |      |                 |
               |      +-----+           |
	       |            |           |
	B4 ----+--------X --+---- X ----+



 


	A5 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C5
               |      |                 |
               |      +-----+           |
	       |            |           |
	B5 ----+--------X --+---- X ----+




 


	A5 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C5
               |      |                 |
               |      +-----+           |
	       |            |           |
	B5 ----+--------X --+---- X ----+




 


	A6 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C6
               |      |                 |
               |      +-----+           |
	       |            |           |
	B6 ----+--------X --+---- X ----+




 


	A7 ----+-- X ---+-------- X ----+
               |        |               |
	       +------+ |               |
	 	      | |               |
	       +--------+               +---- X ---- C7
               |      |                 |
               |      +-----+           |
	       |            |           |
	B7 ----+--------X --+---- X ----+




identical stages


