A complex constant consists of a pair of real or integer constants.
  The two constants are separated by a comma and enclosed in
  parentheses.  The first constant represents the real part of the
  number and the second constant represents the imaginary part.

  VSI Fortran provides three kind type parameters for data of type
  complex:  COMPLEX(KIND=4) (or COMPLEX*8), COMPLEX(KIND=8) (or
  COMPLEX*16), and COMPLEX(KIND=16).  COMPLEX(KIND=8) is DOUBLE
  COMPLEX.  The type specifier for the complex type is COMPLEX; the
  type specifier for the double complex type is DOUBLE COMPLEX.

  If a kind type parameter is specified, the complex constant has the
  kind specified.  If no kind type parameter is specified, the kind
  type of both parts is default real, and the constant is of type
  default complex.

  A COMPLEX (COMPLEX(KIND=4) or COMPLEX*8) constant has
  the form:

   (c,c)

    c   Is an integer or REAL (REAL(KIND=4) or REAL*4)
        constant

  A DOUBLE COMPLEX (COMPLEX(KIND=8) or COMPLEX*16) constant
  has the form:

   (c,c)

    c   Is an integer, REAL (REAL(KIND=4) or REAL*4), or
        DOUBLE PRECISION (REAL(KIND=8) or REAL*8) constant.
        At least one of the pair must be a DOUBLE PRECISION
        constant.

  A COMPLEX(KIND=16) or COMPLEX*32 constant has the form:

   (c,c)

    c   Is an integer, REAL (REAL(KIND=4) or REAL*4),
        DOUBLE PRECISION (REAL(KIND=8) or REAL*8), or
        REAL (KIND=16) (or REAL*16) constant.  At least
        one of the pair must be a a REAL(KIND=16)constant.

  Note that the comma and parentheses are required.