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

int main (int argc, char *argv[])
{
  int rank, size;
  MPI_Init(&argc, &argv);
  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  MPI_Comm_size(MPI_COMM_WORLD, &size);
  printf( "Hello world %d/%d\n", rank, size);
  MPI_Finalize();
}