!********************************************************************
! program    : mpi_samp1.f90
! programmer : makoto nakajima
! description: hello, world!
! date       : april 25, 2006
!********************************************************************
program main
	implicit none     !prohibit implicit declaration of variables
	include 'mpif.h'  !include mpi library

	!******* variables related mpi *******
	integer:: ierror !return error message from mpi subroutines
	integer:: id     !identification number of each processor
	integer:: nproc  !total number of processors

	!******* initialization *******
	!initialization of mpi environment
	call mpi_init(ierror)

	!obtain id for each node
	call mpi_comm_rank(mpi_comm_world, id, ierror)

	!returns the number of nodes
	call mpi_comm_size(mpi_comm_world, nproc, ierror)

	!******* main part of program *******
	!each node prints out.
	!notice that each node prints out once, with different value of id.
	print *, 'hello, world! i am node ',id

	!******* finalize mpi environment *******
	call mpi_finalize(ierror)

end program main