###########  fib
# 
( 0 

  /spur fib
	arg 0
	int 2
	ifge 1
	# less than 2
	int 1
	return

	# 2 or more
1
	arg 0
	int 1
	sub
	call 1@ fib 1
  1@
	arg 0
	int 2
	sub
	call 2@ fib 1
  2@

	add
	return
)
#
######################  Direct
#
   int 1
   call fib 1
   exit