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#include "mpi.h"#include <stdio.h>int main(argc,argv)int argc;char *argv[];  {int numtasks, rank, next, prev, buf[2], tag1=1, tag2=2;MPI_Request reqs[4];MPI_Status stats[4];MPI_Init(&argc,&argv);MPI_Comm_size(MPI_COMM_WORLD, &numtasks);MPI_Comm_rank(MPI_COMM_WORLD, &rank);prev = rank-1;next = rank+1;if (rank == 0)  prev = numtasks - 1;if (rank == (numtasks - 1))  next = 0;MPI_Irecv(&buf[0], 1, MPI_INT, prev, tag1, MPI_COMM_WORLD, &reqs[0]);MPI_Irecv(&buf[1], 1, MPI_INT, next, tag2, MPI_COMM_WORLD, &reqs[1]);MPI_Isend(&rank, 1, MPI_INT, prev, tag2, MPI_COMM_WORLD, &reqs[2]);MPI_Isend(&rank, 1, MPI_INT, next, tag1, MPI_COMM_WORLD, &reqs[3]); MPI_Waitall(4, reqs, stats);MPI_Finalize();}