.data
nl:	
	.asciiz "\n"
	.text
	.globl main
main:
	subu	$sp, $sp, 24
	sw	$ra, 16($sp)

	li	$a0, 10         # call fact with arg $a0
	jal	fact

	move	$a0, $v0        # print_int $a0
        li 	$v0, 1
        syscall

        li 	$v0, 4          # print_string "\n"
        la 	$a0, nl
        syscall

	lw	$ra, 16($sp)
	addiu	$sp, $sp, 24
	jr	$ra

fact:
	subu	$sp, $sp, 32
	sw	$ra, 20($sp)
	sw	$s0, 16($sp)    # save local $s0 to avoid clobber

	move	$s0, $a0
	bgtz	$s0, $L2        # goto $L2 if arg is > 0
	li	$v0, 1          # return 1 if arg is <= 0
	jr	$L1

$L2:
	subu	$a0, $s0, 1     # new arg to fact is arg-1
	jal	fact
	mul	$v0, $s0, $v0   # note that $s0 is saved and restored

$L1:
	lw	$ra, 20($sp)
	lw	$s0, 16($sp)    # restore $s0
	addiu	$sp, $sp, 32
	jr	$ra