assume cs:code, ds:data
code segment
begin:
   jmp main
   chislo dw 0
   mult10 dw 1

main proc near
   mov ax, data
   mov ds,Ax

    mov ah, 09h
    lea dx, msg1
    int 21h

    mov ah, 0ah
    lea dx,param
    int 21h
    lea si,field -1
    mov bh,0
    mov bl, actlen

    call InNumber
    mov ax,chislo
    mov a1,ax

    mov chislo,0
    mov mult10,1

    mov ah, 09h
    lea dx,new_line
    int 21h

    mov ah, 09h
    lea dx, msg2
    int 21h


    mov ah, 0ah
    lea dx,param
    int 21h


   lea si,field - 1
   mov bh,0
   mov bl, actlen

   call InNumber

   mov ax,chislo
   mov a2,ax

    mov BX, a1
    mov CX, a2
    cmp BX, CX
    JG More
    JL Less
    JE Equal


        More:
        mov ax, a2
        cwd
        add ax, a1
        cwd
        mov bx, a1
        sub bl, 1
        idiv bx
        cwd
        mov word ptr chislo, ax
        mov word ptr chislo+2, dx
        jmp output

    mov ax, a2
    cwd
    mov bx, a2
imul bx
mov bx, 8
idiv bx
cwd
mov word ptr chislo, ax
mov word ptr chislo+2, dx
jmp output
;__________________________________________


    Equal:
    mov ax, 23
    mov dx, 0
    mov word ptr chislo, ax
    mov word ptr chislo+2, dx
;__________________________________________


output:
mov chislo, ax


 call FromNumber


mov ah, 09h
 lea dx,new_line
int 21h


 mov ah, 09h
lea dx, msg
int 21h

mov ah, 09h
lea dx,otvet
int 21h

mov ah, 0ah
lea dx,param
int 21h
mov ax,4c00h
int 21h
ret
main endp


InNumber proc
;---------------------------
mov cx,10


b20:
mov al,[si+bx]
and ax, 000fh
mul mult10
add chislo, ax
mov ax,mult10;
mul cx
mov mult10,ax
dec bx
jnz b20
ret
InNumber endp




FromNumber proc
mov cx,0010;
lea si, otvet + 5
mov ax,chislo

mov bx, ax
and bx, 8000h
cmp bx, 8000h
jb  plus

    mov bx, ax
    mov ax, 65535
    sub ax, bx
    add ax, 1

    mov bx, 1
plus:
c20:
cmp ax,0010
jb c30
xor dx,dx
div cx
or dl,30h
mov [si],dl
dec si
jmp c20

c30:
or al,30h
mov [si],al

cmp bx, 1
je addminus
ret
addminus:
dec si
mov al, zminus
mov [si], al
ret
FromNumber endp

code ends

data segment
new_line db 0dh,0ah,'$'
msg db 'Result: $'
msg1 db 'Input a: $'
msg2 db 'Input b: $'
otvet db '      $'
zminus db '-'
a1 dw ?
a2 dw ?
param label byte
maxlen db 20
actlen db ?
field db 20 dup(' ')

data ends
stk segment
db 256 dup (?)
stk ends
end begin