def is_Sub_Array(A,B,n,m):
     
    i = 0; j = 0; 
    while (i < n and j < m):  
        if (A[i] == B[j]): 
            i += 1; 
            j += 1; 
            if (j == m): 
                return True;  
        else: 
            i = i - j + 1; 
            j = 0;       
    return False; 
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] 