def is_Isomorphic(str1,str2):
              
    dict_str1 = {}
    dict_str2 = {}
    for i, value in enumerate(str1):
        dict_str1[value] = dict_str1.get(value,[]) + [i]        
    for j, value in enumerate(str2):
        dict_str2[value] = dict_str2.get(value,[]) + [j]
    if sorted(dict_str1.values()) == sorted(dict_str2.values()):
        return True
    else:
        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] 