#include <mpi.h>
#include <stdio.h>
int main(int argc, char **argv) {
int result;
int rank, size, i;
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Reduce(&rank, &result, 1, MPI_INT, MPI_SUM, 0,
MPI_COMM_WORLD);
if(rank == 0)
printf("Total is %d\n", result);
MPI_Finalize();
return 0;
}