#include <stdio.h>
#include <mpi.h>

int main (int nargs, char** args)
{
  int size, my_rank,i;
  MPI_Init (&nargs, &args);
  MPI_Comm_size (MPI_COMM_WORLD, &size);
  MPI_Comm_rank (MPI_COMM_WORLD, &my_rank);

  for (i=0; i<size; i++) {
    MPI_Barrier (MPI_COMM_WORLD);
    if (i==my_rank) {
      printf("Hello world, I've rank %d out of %d procs.\n",
             my_rank, size);
      fflush (stdout);
    }
  }

  MPI_Finalize ();
  return 0;
}