def smallestIndif(instance):
	""" Returns the size of the smallest indifference class of any voter of the instance.

		:param instance: The instance.
		:type instance: preflibtools.instance.preflibinstance.PreflibInstance

		:return: The size of the smallest indifference class of the instance.
		:rtype: int
	"""
	return min([len(p) for o in instance.orders for p in o if len(p) > 0] + [instance.nbAlternatives])