64-bit signed binary integer

Sample Fortran usage COBOL subroutine
INTEGER*8 X
X = 5
CALL FCBC64I(X)
PRINT *,
1  'UPDATED VALUE IN FORTRAN:', X
END
IDENTIFICATION DIVISION.
PROGRAM-ID. FCBC64I.
ENVIRONMENT DIVISION.
DATA DIVISION.
LINKAGE SECTION.
1   X  PIC S9(18) USAGE IS BINARY.
PROCEDURE DIVISION USING X.
  DISPLAY "COBOL ARG VALUE: ", X.
  ADD 1 TO X.
  EXIT PROGRAM.
END PROGRAM FCBC64I.