fix the bugs.

The program will get the value to calculate the factorial of$,$ which is at x$4000,$ and store the factorial result in x$30$FF

Reminder to not assume the initial value of registers.

; This program calculates X$!($X factorial$).$ It can calculate

; different numbers $(4!,6!,$ etc.$)$ by changing the value of the first memory

; location at the bottom of the code.

; The program does not account for zero or negative numbers as input.

; Register functions

; R$0-$ always x$0$

; R$1-$ multiplication results

; R$2-$ always $-1$

; R$3-$ counter for outer loop

; R$4-$ counter for inner loop

; R$5-$ current sum

x$3000$

LD R$1,$ INPUT ; Load INPUT into R$2$ using label

LD R$2,$x$300$F ; Load $-1$ into R$2$ from below

ADD R$3,$R$1,$R$2$ ; R$3$ contains input number $-1$

ADD R$3,,$R$3,$R$2$ ; R$3$ contains input number $-2$

; $($initializes outer count$)$

OUTERLOOP ADD R$4,$R$0,$R$3$ ; Copy outer count into inner count

; This loop multiplies via addition $(6$x$5=6+6+6+6+6=30,$

; $30$x$4=30+30+30+30=120,$ etc$)$

INNERLOOP ADD R$5,$R$5,$R$1$ ; Increment sum

ADD R$4,$R$4,$R$2$ ; Decrement inner count

BRzp INNERLOOP ; Branch to inner loop if inner count

; is positive or zero

ADD R$1,$R$0,$R$5$ ; R$1$ now contains sum result from inner loop

LD R$5,$x$300$E ; Clear R$5($previous sum$)$ to $0$

ADD R$3,$R$3,$R$2$ ; Decrement outer count

BRpz OUTERLOOP ; Branch to outer loop if outer count

; is positive or zero

ST R$1,$ xxxx ; factorial result is stored in the memory location $($x$30$FF$)$

HALT

$.$FILL x$0000$ ; Can be used to initialize registers

$.$FILL xFFFF ; $2\text{'}$s complement of $1($i$.$e$.-1)$

INPUT $.$FILL x$4000$

RESULT $.$FILL x$30$FF ; At program completion, the result is stored here