some initial function like

  v = setup()
  if v == 1:
    side_effect_1()
  elif v > 1:
    side_effect_1()
    side_effect_2(v)
  else:
    raise Exception()

  v = setup()
  if v < 1:
    raise Exception()
  
  side_effect_1()
  if v > 1:
    side_effect_2(v)