Input two integer number not greater than nine and output their sum in Assembly

.MODEL SMALL
.STACK 100H
.DATA
 MSG DB 'THE SUM OF $'
 MSG2 DB ' AND $'
 MSG3 DB ?,'IS $'
.CODE
MAIN PROC
 
 MOV AH,1
 
 INT 21H
 MOV BL,AL
 
 INT 21H
 
 INT 21H
 MOV CL,AL
 
 MOV AH,2
 
 MOV DL,0DH
 INT 21H
 
 MOV DL,0AH
 INT 21H
 
 MOV AX,@DATA
 MOV DS,AX
 
 LEA DX,MSG
 MOV AH,9
 INT 21H
 
 MOV AH,2
 MOV DL,BL
 INT 21H
 
 LEA DX,MSG2
 MOV AH,9
 INT 21H
 
 MOV AH,2
 MOV DL,CL
 INT 21H
 
 LEA DX,MSG3
 MOV AH,9
 INT 21H
 
 
 SUB BL,30H
 SUB CL,30H
 ADD BL,CL
 MOV DL,BL
 ADD DL,30H
 MOV AH,2
 INT 21H
 
 MOV AH,4CH
 INT 21H
 
 MAIN ENDP
END MAIN