#include <stdio.h>
#include <stdlib.h>

#include "mpi.h"

int main ( int argc, char *argv[] )

{
  int ierr;
  int master = 0;
  int my_id;
  int num_procs;
  /*
  Initialize MPI.
  */
  ierr = MPI_Init ( &argc, &argv );
  /*
  Get the number of processes.
  */
  ierr = MPI_Comm_size ( MPI_COMM_WORLD, &num_procs );
  /*
  Get the individual process ID.
  */
  ierr = MPI_Comm_rank ( MPI_COMM_WORLD, &my_id );
  /*
  Print a message.
  */
  if ( my_id == master ) 
    {
      printf ( "\n" );
      printf ( "HELLO_WORLD - Master process:\n" );
      printf ( "  A simple C program using MPI.\n" );
      printf ( "\n" );
      printf ( "  The number of processes is %d\n", num_procs );
    }

  printf ( "\n" );
  printf ( "  Process %d says 'Hello, world!'\n", my_id );

  /*
  Shut down MPI.
  */
  ierr = MPI_Finalize ( );

  return 0;
}