#include <mpi.h>;
int main(int argc, char** argv) {
  MPI_Init(NULL, NULL);

  int world_size;
  MPI_Comm_size(MPI_COMM_WORLD, &world_size);

  int world_rank;
  MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);

  printf("Hello world from, rank %d"
         " out of %d processors\n",
         world_rank, world_size);

  MPI_Finalize();
  return 0;
}