Program to substrate two number in COBOL..??

IDENTIFICATION DIVISION.
PROGRAM-ID. AAA.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 AA.
     02 A PIC 9(2).
     02 B PIC 9(2).
     02 DIFF PIC 9(2).
PROCEDURE DIVISION.
P1.
     DISPLAY "ENTER THE TWO NUMBER".
     ACCEPT A.
     ACCEPT B.
     COMPUTE DIFF = A + B.
     DISPLAY "DIFFERENCE=", DIFF.
     STOP RUN.