def check_min_heap(arr, i):
    
    if 2 * i + 2 > len(arr):
        return True
    left_child = (arr[i] <= arr[2 * i + 1]) and check_min_heap(arr, 2 * i + 1)
    right_child = (2 * i + 2 == len(arr)) or (arr[i] <= arr[2 * i + 2] 
                                      and check_min_heap(arr, 2 * i + 2))
    return left_child and right_child
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] 