!-----------------------------------------------------------------------
! Original CCM without handshaking should look like this
!-----------------------------------------------------------------------

      program main

      include 'mpif.h'
      implicit none

      integer ierr, myProc
      integer CCM_World
      integer local_sum

! MPI_COMM_WORLD is a MACRO substitution, not a variable. We recommend 
! not to use it in your code. Instead use a VARIABLE with a name 
! more specific to your code, such as CCM_WORLD.
!
! It's necessary to call MPI_COMM_DUP( MPI_COMM_WORLD, CCM_World, ierr)
! to copy the communicator pointered by  MPI_COMM_WORLD to a
! communicator pointered by CCM_WORLD.
! 
! Later on, when MPH_setup are invoked, the appropriate COMMUNICATOR
! is passed on directly to CCM_WORLD; no changes in the original codes
! is needed.

      call MPI_INIT (ierr)
      call MPI_COMM_DUP( MPI_COMM_WORLD, CCM_World, ierr)
      call MPI_COMM_RANK (CCM_World, myProc, ierr)

      call MPI_REDUCE (myProc, local_sum, 1, MPI_INTEGER, MPI_SUM,
     &                 0, CCM_World, ierr)
      if (myProc == 0) then
         write(*,*)' sum of local ranks in ccm is ', local_sum
      endif

      call MPI_FINALIZE (ierr)
      end