






'''simple docstring'''




from __future__ import annotations

from collections.abc import Iterator







class       __lowercase					:

	def __init__(      self   :						int  ,					UpperCAmelCase_   :						int):
			UpperCamelCase__				:					int					=					value
			UpperCamelCase__				:					Node | None					=					None
			UpperCamelCase__				:					Node | None					=					None







class       __lowercase					:

	def __init__(      self   :						int  ,					UpperCAmelCase_   :						Node):
			UpperCamelCase__				:					Optional[int]					=					tree

	def      __UpperCamelCase							(      self   :						str  ,					UpperCAmelCase_   :						Node | None):
			if node is None:
					return 0
			return node.value + (
			    self.depth_first_search(node.left) + self.depth_first_search(node.right)
			)





	def __iter__(      self   :						str):
			yield self.depth_first_search(self.tree)


if __name__ == "__main__":
		import doctest

		doctest.testmod()












'''simple docstring'''




def       __UpperCAmelCase						(  lowerCamelCase_     ,      lowerCamelCase_)							->     list[str]:
		return [sentence[i : i + ngram_size] for i in range(len(lowerCamelCase_) - ngram_size + 1)]


if __name__ == "__main__":
		from doctest import testmod

		testmod()




