.model tiny
        .data
        .code
        mov ax,@data
        mov ds,ax
        mov cl,0
        mov ch,0
        mov dx,0
   su:  mov ah,1
        int 21h
        mov ah,0
        push ax
        inc cl
        cmp al,'9'
        jne su
etic:   pop bx
        sub bx,48
        cmp bx,5
        ja skip
        inc ch
        add dx,bx
 skip:  dec cl
        jnz etic
        cmp ch,0
        je fine
        mov ax,dx
        div ch
        add al,48
        mov ah,0eh
        int 10h
fine:   mov ax,4c00h
        int 21h
        end