* ==== TYPE: ADV-MATCH-10FILES ====
      * FEATURE: 10 files, only 2 with key comparison
      * STATEMENT: IF / OPEN / READ
      * BRANCHES: 2, DECISIONS: 1
      * ADVERSARIAL: Multi-file program that's NOT matching
       IDENTIFICATION DIVISION.
       PROGRAM-ID. TENFL.
       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT F1 ASSIGN TO 'F1.DAT'.
           SELECT F2 ASSIGN TO 'F2.DAT'.
           SELECT F3 ASSIGN TO 'F3.DAT'.
           SELECT F4 ASSIGN TO 'F4.DAT'.
           SELECT F5 ASSIGN TO 'F5.DAT'.
           SELECT F6 ASSIGN TO 'F6.DAT'.
           SELECT F7 ASSIGN TO 'F7.DAT'.
           SELECT F8 ASSIGN TO 'F8.DAT'.
           SELECT F9 ASSIGN TO 'F9.DAT'.
           SELECT F10 ASSIGN TO 'F10.DAT'.
       DATA DIVISION.
       FILE SECTION.
       FD F1. 01 R1 PIC X(80).
       FD F2. 01 R2 PIC X(80).
       FD F3. 01 R3 PIC X(80).
       FD F4. 01 R4 PIC X(80).
       FD F5. 01 R5 PIC X(80).
       FD F6. 01 R6 PIC X(80).
       FD F7. 01 R7 PIC X(80).
       FD F8. 01 R8 PIC X(80).
       FD F9. 01 R9 PIC X(80).
       FD F10. 01 R10 PIC X(80).
       WORKING-STORAGE SECTION.
       01 WS-KEY     PIC X(10).
       01 WS-COUNT   PIC 9(5) VALUE 0.
       PROCEDURE DIVISION.
       MAIN.
           OPEN INPUT F1 F2 F3 F4 F5 F6 F7 F8 F9 F10.
           READ F1 INTO R1 AT END MOVE 'Y' TO WS-EOF.
           ADD 1 TO WS-COUNT.
           IF WS-COUNT > 0
               DISPLAY 'OK'.
           CLOSE F1 F2 F3 F4 F5 F6 F7 F8 F9 F10.
           STOP RUN.