       IDENTIFICATION DIVISION.
       PROGRAM-ID. TRIANGLE.
       DATA                             DIVISION.
       WORKING-STORAGE                  SECTION.
       01 WRK-AREA.
         03  IN-DATA.
           05  IN-DATA-1                PIC X(01) OCCURS 20.
         03  OUTNUM-X.
           05  OUTNUM-X-1               PIC X(01) OCCURS 6.
         03  OUTNUM-AB                  PIC 9(06).
         03  OUTNUM-BC                  PIC 9(06).
         03  IDX1                       PIC 9(02).
         03  IDX2                       PIC 9(02).
         03  IDX3                       PIC 9(02).
         03  CNT                        PIC 9(01).
         03  CNT2                       PIC 9(02).
         03  MENSEKI                    PIC 9(08).
         03  MENSEKI-X REDEFINES MENSEKI.
           05  MENSEKI-X-1              PIC X(01) OCCURS 8.
         03  MENSEKI-D01 REDEFINES MENSEKI.
           05  MENSEKIM1                  PIC 9(07).
           05  MENSEKI01                  PIC 9(01).
         03  MENSEKI-D02 REDEFINES MENSEKI.
           05  MENSEKIM2                  PIC 9(06).
           05  MENSEKI02                  PIC 9(02).
         03  MENSEKI-D03 REDEFINES MENSEKI.
           05  MENSEKIM3                  PIC 9(05).
           05  MENSEKI03                  PIC 9(03).
         03  MENSEKI-D04 REDEFINES MENSEKI.
           05  MENSEKIM4                  PIC 9(04).
           05  MENSEKI04                  PIC 9(04).
         03  MENSEKI-D05 REDEFINES MENSEKI.
           05  MENSEKIM5                  PIC 9(03).
           05  MENSEKI05                  PIC 9(05).
         03  MENSEKI-D06 REDEFINES MENSEKI.
           05  MENSEKIM6                  PIC 9(02).
           05  MENSEKI06                  PIC 9(06).
         03  MENSEKI-D07 REDEFINES MENSEKI.
           05  MENSEKIM7                  PIC 9(01).
           05  MENSEKI07                  PIC 9(07).
         03  MENSEKI-D08 REDEFINES MENSEKI.
           05  MENSEKI08                  PIC 9(08).

       PROCEDURE DIVISION.
       
       INITIALIZE  WRK-AREA.
       
       ACCEPT  IN-DATA  FROM  SYSIN.
       
       MOVE  1  TO  CNT.
       MOVE  0  TO  CNT2.

       PERFORM  VARYING IDX1 FROM 1 BY 1 UNTIL  CNT > 2
       
         IF IN-DATA-1(IDX1) = SPACE
         THEN
           IF  IDX2 = 0
           THEN
             CONTINUE
           ELSE
             IF  CNT = 1
             THEN
               MOVE  OUTNUM-X(1:IDX2)  TO  OUTNUM-AB
               COMPUTE  CNT = CNT + 1
               MOVE  SPACE             TO  OUTNUM-X
               MOVE  0                 TO  IDX2
             ELSE
               MOVE  OUTNUM-X(1:IDX2)  TO  OUTNUM-BC
               COMPUTE  CNT = CNT + 1
               MOVE  SPACE             TO  OUTNUM-X
               MOVE  0                 TO  IDX2
             END-IF
           END-IF
         ELSE
           COMPUTE  IDX2 = IDX2 + 1
           MOVE  IN-DATA-1(IDX1)     TO  OUTNUM-X-1(IDX2)
         END-IF
       
       END-PERFORM.

       COMPUTE MENSEKI = OUTNUM-AB * OUTNUM-BC / 2.
       
       
       
       PERFORM  VARYING IDX3 FROM 1 BY 1 UNTIL  IDX3 > 8
         IF  MENSEKI-X-1(IDX3) = ZERO
         THEN
           CONTINUE
         ELSE
           COMPUTE  CNT2 = CNT2 + 1
       END-PERFORM.
       
       EVALUATE  CNT2
       WHEN 1
         DISPLAY "この三角形の面積は" MENSEKI01 "です。"
       WHEN 2
         DISPLAY "この三角形の面積は" MENSEKI02 "です。"
       WHEN 3
         DISPLAY "この三角形の面積は" MENSEKI03 "です。"
       WHEN 4
         DISPLAY "この三角形の面積は" MENSEKI04 "です。"
       WHEN 5
         DISPLAY "この三角形の面積は" MENSEKI05 "です。"
       WHEN 6
         DISPLAY "この三角形の面積は" MENSEKI06 "です。"
       WHEN  7
         DISPLAY "この三角形の面積は" MENSEKI07 "です。"
       WHEN OTHER
         DISPLAY "この三角形の面積は" MENSEKI08 "です。"
       END-EVALUATE.

       STOP RUN.

