program hello

C     hello world in FORTRAN

      implicit none
      include 'mpif.h'

      integer me, nprocs, ierr
      integer status(MPI_STATUS_SIZE)
      character msg(13)

      call MPI_INIT(ierr)

      call MPI_COMM_SIZE(MPI_COMM_WORLD, nprocs, ierr)
      call MPI_COMM_RANK(MPI_COMM_WORLD, me, ierr)

      IF (me .EQ. 0) THEN
	print *, 'I am master. I am sending the message.'
        call MPI_SEND('Hello World!', 13, MPI_CHARACTER, 1, 100,
     $                MPI_COMM_WORLD, ierr)
      ELSE
        print *, 'I am slave. I am receiving the message.'
        call MPI_RECV(msg, 13, MPI_CHARACTER, 0, 100,
     $                MPI_COMM_WORLD, status, ierr)
	print *, 'The message is: ', msg
      endif

      call MPI_FINALIZE(ierr)

      end