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

int main(int argc, char **argv )
 {
  int i,myid, numprocs;
  int *ids;
  MPI_Status status;

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
  MPI_Comm_rank(MPI_COMM_WORLD, &myid); 
  if (myid == 0)
   ids = (int *) malloc(numprocs * sizeof(int));
  MPI_Gather(&myid,1,MPI_INT,ids,1,MPI_INT,0,MPI_COMM_WORLD);
  if (myid == 0)
   for (i=0;i<numprocs;i++)
    printf("%d\n",ids[i]);
  MPI_Finalize();
  return 0;
 }