program main
      implicit none
*     Remove the following line if you are using Omni.
      include 'omp_lib.h'

      integer i_am, k, v(0:4)
      data    v / -1, -1, -1, -1, -1 /

*     Max number of procs and threads. 
      print*, "num_procs   = ", omp_get_num_procs()
      print*, "max_threads = ", omp_get_max_threads()

*     I have given the following unix-command: 
*     setenv OMP_NUM_THREADS 10  (4 is enough).

*     Set no. of threads dynamically.
      call omp_set_num_threads(4)

*     A parallel section.
*$OMP parallel private(i_am) shared(v)
*$OMP single
      print*, "num_threads = ", omp_get_num_threads()
*$OMP end single
      i_am    = omp_get_thread_num()
      v(i_am) = i_am
*$OMP end parallel

      print*, "v = ", v

*     A parallel do-loop. 
*$OMP parallel do private(k) shared(v)
      do k = 0, 4
        v(k) = k * k
      end do
*$OMP end parallel do 

      print*, "v = ", v

      end