.text
        .globl  __start
__start:
        li      $v0, 4           # mesg1 asking for a number
        la      $a0, msg1
        syscall
        li      $v0,5           # system call that reads an integer
        syscall 
        move    $t0, $v0

        li      $t1, 0          # initialize loop counter 
        li      $t2, 1          # initialize total sum to 0

loop: addi    $t1, $t1, 1     # increment loop counter by 1
         mul    $t2, $t2, $t1   # update value of sum
         beq     $t0, $t1, exit  # if if counter = N, goto exit label
         j       loop            # otherwise loop again

exit:   li      $v0, 4          # print mesg2
        la      $a0, msg2
        syscall

li      $v0,1                   # print factorial
        move    $a0, $t2
        syscall
        li      $v0,4           # print an end of line
        la      $a0, cr
        syscall
        li      $v0,10          # exit
        syscall
        .data

msg1:   .asciiz "Enter a integer number:  "
msg2:   .asciiz "Factorial of the number  =   "
cr:     .asciiz "\n"