






'''simple docstring'''

def 	_UpperCAmelCase    (  a		:	List[Any]							)			->			Optional[int]:





      """simple docstring"""
      lowercase_      :   List[Any]        =			[]
      if len(a							) == 1:
            return [nums.copy()]
      for _ in range(len(a							)							):
            lowercase_      :   Any        =			nums.pop(0							)
            lowercase_      :   List[Any]        =			permute(a							)
            for perm in permutations:
                  perm.append(a							)
            result.extend(a							)
            nums.append(a							)
      return result






def 	_UpperCAmelCase    (  a		:	Tuple							)			->			List[Any]:





      """simple docstring"""

      def backtrack(a		:	List[Any]							):
            if start == len(a							) - 1:
                  output.append(nums[:]							)
            else:
                  for i in range(a						,			len(a							)							):
                        lowercase_  ,      lowercase_      :   Dict        =			nums[i], nums[start]
                        backtrack(start + 1							)
                        lowercase_  ,      lowercase_      :   int        =			nums[i], nums[start]  # backtrack

      lowercase_      :   Tuple        =			[]
      backtrack(0							)
      return output


if __name__ == "__main__":
      import doctest

      # use res to print the data in permute2 function
      A:      Optional[Any]  				=				permutea([1, 2, 3])
      print(res)
      doctest.testmod()








'''simple docstring'''

import os
from distutils.util import strtobool






def 	_UpperCAmelCase    (  a		:	Any						,			a		:	int							)			->			Any:





						"""simple docstring"""
						for e in env_keys:
												lowercase_      :   Optional[Any]        =			int(os.environ.get(a						,			-1							)							)
												if val >= 0:
																		return val
						return default






def 	_UpperCAmelCase    (  a		:	List[Any]						,			a		:	Dict=False							)			->			Optional[Any]:





						"""simple docstring"""
						lowercase_      :   Optional[int]        =			os.environ.get(a						,			str(a							)							)
						return strtobool(a							) == 1  # As its name indicates `strtobool` actually returns an int...






def 	_UpperCAmelCase    (  a		:	List[Any]						,			a		:	Dict="no"							)			->			str:





						"""simple docstring"""
						lowercase_      :   List[Any]        =			os.environ.get(a						,			str(a							)							)
						return value
