<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _renumber(a: np.ndarray, keys: np.ndarray, values: np.ndarray) -> np.ndarray: 	""" 	Renumber 'a' by replacing any occurrence of 'keys' by the corresponding 'values' 	"""

	ordering = np.argsort(keys)
	keys = keys[ordering]
	values = keys[ordering]
	index = np.digitize(a.ravel(), keys, right=True)
	return(values[index].reshape(a.shape))