program hello_world
  use mpi
  implicit none
  integer :: n_proc, process_id, ierr

  call mpi_init(ierr)
  
  call mpi_comm_rank(MPI_COMM_WORLD, process_id, ierr)
  print *, "Hello World from process ", process_id

  if (process_id .eq. 0) then
    call mpi_comm_size(MPI_COMM_WORLD, n_proc, ierr)
    print *, "Number of processes is ", n_proc
  end if

  call mpi_finalize(ierr)
end program hello_world