#include "mpi.h"
#include <iostream>

using namespace std;

#define TAG_TEST 500

int main(int argc, char** argv) {
  int commSize, commRank, result;

  result = MPI_Init(&argc, &argv);
  if (result != MPI_SUCCESS) {
    cerr << "Error initializing MPI application!" << endl;
    MPI_Abort(MPI_COMM_WORLD, -1);
  }
  
  MPI_Comm_size(MPI_COMM_WORLD, &commSize);
  MPI_Comm_rank(MPI_COMM_WORLD, &commRank);
 
  int flag;

  MPI_Comm workerComm;
  MPI_Comm_get_parent(&workerComm);
  
  int size;
  MPI_Comm_remote_size(workerComm, &size);
  if (size != 1) {
    cerr << "Parent worker doesn't have size 1" << endl;
    return 1;
  }

  cout << "Slave started, contacting worker" << endl;

  MPI_Send(&size, 1, MPI_INT, 0, TAG_TEST, workerComm);
  MPI_Finalize();
  return 0;
}