def get_odd_occurence(arr, arr_size):
  
  for i in range(0, arr_size):
    count = 0
    for j in range(0, arr_size):
      if arr[i] == arr[j]:
        count += 1
    if (count % 2 != 0):
      return arr[i]
  return -1
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] 