def No_of_Triangle(N,K):
    
    if (N < K):
        return -1;
    else:
        Tri_up = 0;
        Tri_up = ((N - K + 1) *(N - K + 2)) // 2;
        Tri_down = 0;
        Tri_down = ((N - 2 * K + 1) *(N - 2 * K + 2)) // 2;
        return Tri_up + Tri_down;
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] 