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

main(int argc, char **argv)
{
    MPI_Init(&argc, &argv);
    MPI_Comm newcomm;
    int dims [] = {3, 3},
        periodic [] = {0, 0},
        reorder = 0;
    int rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Cart_create(MPI_COMM_WORLD, 2, dims, periodic, reorder, &newcomm);
    int coords[2];
        MPI_Cart_coords(newcomm, rank, 2, coords);
//      printf("%d: (%d, %d)\n", rank, coords[0], coords[1]);
    int source, destination;
    MPI_Cart_shift(newcomm, 0, 1, &source, &destination);
    printf("%d, %d, %d\n", source, rank, destination);

    MPI_Finalize();
}