anchor.diff:  
   
       write (*,*) "Perfect numbers"
  -    write (*,*) "==============="
  +    write (*,*) "---------------"
       call system_clock(tic)
       call perfect_numbers(pn_limit, res_pn)
       call system_clock(toc)
  
positive.code: 
      call system_clock(count_rate = rate)
  
  #ifdef __GFORTRAN__
      write (*, *) "Compiler infos"
      write (*, *) "=============="
  
      write (*, *) 'Compiler version: ', compiler_version()
      write (*, *) 'Compiler options: ', compiler_options()
      write (*, *)
  #endif
  
      write (*,*) "Fibonacci numbers"
      write (*,*) "================="
      call system_clock(tic)
      res_int = fib_naive(35)
      call system_clock(toc)
  
negative.code: program benchmark
  
      use iso_fortran_env, only: compiler_version, compiler_options 
      use omp_lib, only: omp_get_thread_num, omp_get_num_threads
  
      use fibonacci
      use perfect_number
  