



'''simple docstring'''
import os
from distutils.util import strtobool


def      lowercase_		(      lowerCAmelCase__		:     Any	,							lowerCAmelCase__		:     Optional[Any]       ):

			"""simple docstring"""





			for e in env_keys:
						__UpperCAmelCase      :					Tuple   =   int(os.environ.get(__lowerCAmelCase	,							-1       )       )
						if val >= 0:
									return val
			return default


def      lowercase_		(      lowerCAmelCase__		:     int	,							lowerCAmelCase__		:     Any=False       ):

			"""simple docstring"""





			__UpperCAmelCase      :					Any   =   os.environ.get(__lowerCAmelCase	,							str(__lowerCAmelCase       )       )
			return strtobool(__lowerCAmelCase       ) == 1  # As its name indicates `strtobool` actually returns an int...






def      lowercase_		(      lowerCAmelCase__		:     int	,							lowerCAmelCase__		:     Tuple="no"       ):

			"""simple docstring"""





			__UpperCAmelCase      :					Union[str, Any]   =   os.environ.get(__lowerCAmelCase	,							str(__lowerCAmelCase       )       )
			return value








'''simple docstring'''


def        __lowerCAmelCase       (__lowerCAmelCase = 50      ):
		_UpperCAmelCase						:				Tuple	    =					[[0] * 3 for _ in range(length + 1      )]

		for row_length in range(length + 1      ):
				for tile_length in range(2					,       5      ):
						for tile_start in range(row_length - tile_length + 1      ):
								different_colour_ways_number[row_length][tile_length - 2] += (
								    different_colour_ways_number[row_length - tile_start - tile_length][
								        tile_length - 2
								    ]
								    + 1
								)

		return sum(different_colour_ways_number[length]      )


if __name__ == "__main__":
						print(F'''{solution() = }''')



