def check_IP(Ip):
	import re 
	regex = '''^(25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.( 
				25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.( 
				25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)\.( 
				25[0-5]|2[0-4][0-9]|[0-1]?[0-9][0-9]?)$'''
	 
	if(re.search(regex, Ip)): 
		return ("Valid IP address") 
	else: 
		return ("Invalid IP address") 
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] 