(VAR)
(RULES
c0 -> c5
c0 -> c11
c5 -> c6
c11 -> c12
c1 -> c6
c1 -> c12
c6 -> c7
c12 -> c13
c2 -> c7
c2 -> c13
c7 -> c8
c13 -> c14
c3 -> c8
c3 -> c14
c8 -> c9
c14 -> c15
c4 -> c10
c9 -> c10
c15 -> c10
)