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

int main(int argc, char** argv) {
    // Initialize the MPI environment
    MPI_Init(&argc, &argv);

    // Get the rank of the process and the total number of processes
    int world_rank, world_size;
    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &world_size);

    int number;
    if (world_rank == 0) {
        // Start with the number 0
        number = 0;
        MPI_Send(&number, 1, MPI_INT, world_rank + 1, 0, MPI_COMM_WORLD);
    } else {
        MPI_Recv(&number, 1, MPI_INT, world_rank - 1, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
        number += world_rank; // Add the rank to the number

        if (world_rank < world_size - 1) {
            // Not the last process, so send to the next process
            MPI_Send(&number, 1, MPI_INT, world_rank + 1, 0, MPI_COMM_WORLD);
        } else {
            // Last process prints the final result
            printf("Process %d received number %d\n", world_rank, number);
        }
    }

    // Finalize the MPI environment
    MPI_Finalize();
}