int compare(MPI_Group group2);
int incl(int n, int* ranks, MPI_Group* newgroup);
int excl(int n, int *ranks, MPI_Group * newgroup);
int compare(MPI_Group group2);
int incl(int n, int* ranks, MPI_Group* newgroup);
int excl(int n, int *ranks, MPI_Group * newgroup);