allocate-registers big-case, two, zero, one, fib-proc, sp, n, cont, small, val

	li big-case, recursive-stuff
	li two, 2
	li zero, 0
	li one, 1
	li fib-proc, fib
	li sp, 0

	read n
	li cont, print-answer

fib:
	slt small, n, two
	jeqz small, big-case
	add val, n, zero
	j cont

print-answer:
	write val
	halt

recursive-stuff:
	st cont, sp
	add sp, sp, one
	st n, sp
	add sp, sp, one
	sub n, n, one
	li cont, after-first
	j fib-proc

after-first:
	sub sp, sp, one
	ld n, sp
	st val, sp
	add sp, sp, one
	sub n, n, two
	li cont, after-second
	j fib-proc

after-second:
	sub sp, sp, one
	ld n, sp
	sub sp, sp, one
	ld cont, sp
	add val, val, n
	j cont