#include <stdio.h>
#include <mpi.h>
 
int main(int argc, char** argv) {
    int rank, size, N = 100;
    int sum = 0;
 
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
 
    int local_sum = 0;
    int chunk_size = N / size;
    int start = rank * chunk_size + 1;
    int end = start + chunk_size - 1;
 
    if (rank == size - 1) {
        end = N;
    }
 
    for (int i = start; i <= end; i++) {
        local_sum += i;
    }
 
    MPI_Reduce(&local_sum, &sum, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
 
    if (rank == 0) {
        printf("The sum of numbers from 1 to %d is %d\n", N, sum);
    }
 
    MPI_Finalize();
    return 0;
}
 

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