      IDENTIFICATION DIVISION.
      PROGRAM-ID. 108A.
      DATA DIVISION.
      WORKING-STORAGE SECTION.
      01 INP PIC X(100).
      01 BH  PIC 9(2).
      01 BW  PIC 9(2).
      01 SH  PIC 9(2).
      01 SW  PIC 9(2).
      
      01 ANS PIC 9(5).
      01 ANSS PIC ZZZZ9.
      
      PROCEDURE DIVISION.
      ACCEPT INP.
      UNSTRING INP DELIMITED BY " "
      INTO BH BW.
      
      ACCEPT INP
      UNSTRING INP DELIMITED BY " "
      INTO SH SW.
      
      COMPUTE ANS = ( BH - SH ) * ( BW - SW )
      
      MOVE ANS TO ANSS.
      
      DISPLAY FUNCTION TRIM(ANSS).
      
      STOP RUN.