def METHOD_NAME(args):
  assert len(args) in [0,1]
  if (len(args) == 0):
    n_dynamics_steps = 1
    out = null_out()
  else:
    n_dynamics_steps = max(1, int(args[0]))
    out = sys.stdout
  #
  exercise_reference_impl_quick()
  exercise_featherstone_FDab(out=out)
  exercise_reference_impl_long(n_dynamics_steps=n_dynamics_steps, out=out)
  #
  print(format_cpu_times())