def octal_To_Decimal(n):
      
    num = n; 
    dec_value = 0; 
    base = 1; 
    temp = num; 
    while (temp): 
        last_digit = temp % 10; 
        temp = int(temp / 10); 
        dec_value += last_digit*base; 
        base = base * 8; 
    return dec_value; 
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] 