code: 
  
  """simple docstring"""
  
  
  
  
  __A  :					List[Any]												=	{
      '+': lambda x, y: x + y,
      '-': lambda x, y: x - y,
      '*': lambda x, y: x * y,
      '/': lambda x, y: x / y,
  }
  def      __SCREAMING_SNAKE_CASE		(		lowercase__   ):
  					"""simple docstring"""
  					return c.isdigit()
  def      __SCREAMING_SNAKE_CASE		(		lowercase__   ):
  					"""simple docstring"""
  					A    =      []
  
  					# iterate over the string in reverse order
  					for c in expression.split()[::-1]:
  										# push operand to stack
  										if is_operand(lowercase__   ):
  															stack.append(int(lowercase__   )   )
  
  										else:
  															# pop values from stack can calculate the result
  															# push the result onto the stack again
  															A    =      stack.pop()
  															A    =      stack.pop()
  															stack.append(calc[c](lowercase__    ,							lowercase__   )   )
  
  					return stack.pop()
  
  
  # Driver code
  if __name__ == "__main__":
  	__A  :					List[Any]												=	'+ 9 * 2 6'
  	print(evaluate(test_expression))
  
  	__A  :					List[str]												=	'/ * 10 2 + 4 1 '
  	print(evaluate(test_expression))
  
  
  
  
  
  
style_context: 
  
  """simple docstring"""
  
  
  
  
  def      __SCREAMING_SNAKE_CASE		(		lowercase__    ,							lowercase__   ):
  					"""simple docstring"""
  					A    =      1
  					while b > 0:
  										if b & 1:
  															res *= a
  
  										a *= a
  										b >>= 1
  
  					return res
  def      __SCREAMING_SNAKE_CASE		(		lowercase__    ,							lowercase__    ,							lowercase__   ):
  					"""simple docstring"""
  					A    =      1
  					while b > 0:
  										if b & 1:
  															A    =      ((res % c) * (a % c)) % c
  
  										a *= a
  										b >>= 1
  
  					return res
  
  
  
  
  
  