def extract_even(test_tuple):
  def even_ele(test_tuple, even_fnc): 
  	res = tuple() 
  	for ele in test_tuple: 
  		if isinstance(ele, tuple): 
  			res += (even_ele(ele, even_fnc), ) 
  		elif even_fnc(ele): 
  			res += (ele, ) 
  	return res 
  
  res = even_ele(test_tuple, lambda x: x % 2 == 0)
  return (res) 
def count_ways(n):
	 
	A = [0] * (n + 1) 
	B = [0] * (n + 1) 
	A[0] = 1
	A[1] = 0
	B[0] = 0
	B[1] = 1
	for i in range(2, n+1): 
		A[i] = A[i - 2] + 2 * B[i - 1] 
		B[i] = A[i - 1] + B[i - 2] 
	return A[n] 