3. Here is a simple MPI program. Give a description on what this program is doing. #include "mpi.h" #include int main(int argc, char *argv[]) { int rank, buf; MPI Status status; MPI_Init(&argv, &argc); MPI Comm_rank( MPI_COMM_WORLD, &rank); /* Process 0 sends and Process 1 receives */ } if (rank == 0) { MPI COMM_WORLD); buf = 123456; MPI Send( &buf, 1, MPI_INT, 1, 0, MPI Send( &buf, 1, MPI_INT, 2, 0, MPI COMM_WORLD); } else if (rank 1 || rank 2) { == } MPI COMM_WORLD, &status); printf("Received %d ", buf); MPI Recv( &buf, 1, MPI_INT, 0, 0, MPI_Finalize(); return 0;