bud with pistons and redstone block

triggers by a update

What I expected to happen was a t flip flop

*What actually happened was i created a t-flip plop bud that wont stop

p= piston
r=redstone block
d=reapeter
w=redstone wire
a=air
b=block
aaaww
aaadw
pbbpb here is the layout of it
dwaaa
wwaaa