def modular_sum(arr, n, m):
	 
	if (n > m): 
		return True
	DP = [False for i in range(m)] 
	for i in range(n): 
		if (DP[0]): 
			return True
		temp = [False for i in range(m)] 
		for j in range(m): 
			if (DP[j] == True): 
				if (DP[(j + arr[i]) % m] == False): 
					temp[(j + arr[i]) % m] = True
		for j in range(m): 
			if (temp[j]): 
				DP[j] = True
		DP[arr[i] % m] = True
	return DP[0]
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] 