set! N 8
set! one 1
set! two 2
set! q 2
in! x0
in! x1
sub! q one t
mul! t x1 t
add! t one p
mul! q q q
sub! q one t
mul! t x0 t
add! t one t
mul! p t p
div! N p N
mod! N two N
out! N
