def find_between(s: str, before: str, after: str):
	"""Searches string S and finds the first substring found between the
	BEFORE and AFTER substrings, if they are found.
	
	Returns the indexes of the start and end of the found substring,
	such that s[start:end] would be the substring. (first character, last character + 1)

	If not found, (0,0) is returned. 

	example:
	>>> find_between("hayneedlestack", "hay", "stack")
	(3, 9)

	>>> find_between("hello world", "hay", "stack")
	(0, 0)
	"""
	start = s.find(before) + len(before)
	if start < 0: return 0, 0

	end = s[start:].find(after)
	if end < 0: return 0, 0

	return start, start + end