DOSSEG
.MODEL SMALL
.STACK
.DATA
.CODE

CR EQU 13
LF EQU 10

main PROC
    CALL read_decimal
    MOV DH,DL
    CALL read_decimal
    DEC DL
    MOV AL,DL
    MOV DL,DH
    return:
        INC DL
        CALL write_char
        CALL write_decimal
        CALL CR_LF
        CMP DL,AL
        JB return


    MOV AH, 4CH
    INT 21H
main ENDP

read_decimal PROC
    PUSH AX
    PUSH BX

    MOV BL,10
    XOR AX,AX
  read_decimal_new:
    CALL read_char
    CMP DL,CR
    JE read_decimal_end
    SUB DL,'0'
    MUL BL
    ADD AL,DL
    JMP read_decimal_new
  read_decimal_end:
    MOV DL,AL
    POP BX
    POP AX
    RET
read_decimal ENDP

write_decimal PROC
    PUSH AX
    PUSH CX
    PUSH DX
    PUSH SI

    XOR DH,DH
    MOV AX,DX
    MOV SI,10
    XOR CX,CX
  decimal_non_zero:
    XOR DX,DX
    DIV SI
    PUSH DX
    INC CX
    OR AX,AX
    JNE decimal_non_zero

  decimal_loop:
    POP DX
    CALL write_hexa_digit
    LOOP decimal_loop

    POP SI
    POP DX
    POP CX
    POP AX
    RET
write_decimal ENDP


write_hexa_digit PROC
    PUSH DX
    ADD DL,'0'
    CALL write_char
    POP DX
    RET
write_hexa_digit ENDP

CR_LF PROC
    PUSH DX
    MOV DL,CR
    CALL write_char
    MOV DL, LF
    CALL write_char
    POP DX
    RET
CR_LF ENDP

read_char PROC
    PUSH AX
    MOV AH,1
    INT 21H
    MOV DL,AL
    POP AX
    RET
read_char ENDP

write_char PROC
    PUSH AX
    MOV AH,2
    INT 21H
    POP AX
    RET
write_char ENDP

END main