
"""simple docstring"""



def 	__snake_case  (    SCREAMING_SNAKE_CASE:					str     ,  SCREAMING_SNAKE_CASE:					str						):






							"""simple docstring"""



							assert x is not None
							assert y is not None

							_lowerCAmelCase  	=			len(SCREAMING_SNAKE_CASE						)
							_lowerCAmelCase  	=			len(SCREAMING_SNAKE_CASE						)

							# declaring the array for storing the dp values
							_lowerCAmelCase  	=			[[0] * (n + 1) for _ in range(m + 1						)]  # noqa: E741

							for i in range(1     ,  m + 1						):
														for j in range(1     ,  n + 1						):
																					_lowerCAmelCase  	=			1 if x[i - 1] == y[j - 1] else 0

																					_lowerCAmelCase  	=			max(l[i - 1][j]     ,  l[i][j - 1]     ,  l[i - 1][j - 1] + match						)

							_lowerCAmelCase  	=			''
							_lowerCAmelCase	,		_lowerCAmelCase  	=			m, n
							while i > 0 and j > 0:
														_lowerCAmelCase  	=			1 if x[i - 1] == y[j - 1] else 0

														if l[i][j] == l[i - 1][j - 1] + match:
																					if match == 1:
																												_lowerCAmelCase  	=			x[i - 1] + seq
																					i -= 1
																					j -= 1
														elif l[i][j] == l[i - 1][j]:
																					i -= 1
														else:
																					j -= 1

							return l[m][n], seq


if __name__ == "__main__":
	_snake_case          =						'''AGGTAB'''
	_snake_case          =						'''GXTXAYB'''
	_snake_case          =						4
	_snake_case          =						'''GTAB'''

	_snake_case      ,    _snake_case          =						longest_common_subsequence(a, b)
	print('''len =''', ln, ''', sub-sequence =''', subseq)
	import doctest

	doctest.testmod()








"""simple docstring"""



def 	__snake_case  (    SCREAMING_SNAKE_CASE:					str						):






							"""simple docstring"""



							_lowerCAmelCase  	=			[int(SCREAMING_SNAKE_CASE						) for i in ip_va_address.split('.'						) if i.isdigit()]
							return len(SCREAMING_SNAKE_CASE						) == 4 and all(0 <= int(SCREAMING_SNAKE_CASE						) <= 254 for octet in octets						)


if __name__ == "__main__":
	_snake_case          =						input().strip()
	_snake_case          =						'''valid''' if is_ip_va_address_valid(ip) else '''invalid'''
	print(f'{ip} is a {valid_or_invalid} IP v4 address.')






