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


int main(int argc, char** argv) {
	MPI_Init(NULL, NULL);

	int world_size;
	MPI_Comm_size(MPI_COMM_WORLD, &world_size);

	int world_rank;
	MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
		
	printf("Hello world from rank %d out of %d processors\n", 
			world_rank, world_size);
	fflush(stdout);
	sleep(2);

	for (int i = 0; i < 10; ++i) {
		printf("Rank %d is working...\n", world_rank); 
		fflush(stdout);
		sleep(2);
	}


	printf("Goodbye from rank %d out of %d processors\n", 
			world_rank, world_size);
	
	MPI_Finalize();
}