You should write a simple function that takes string as input and checks if it is a valid Russian postal code, returning `true` or `false`.

A valid postcode should be 6 digits with no white spaces, letters or other symbols. Empty string should also return false. 

Please also keep in mind that a valid post code **cannot start with** `0, 5, 7, 8 or 9`


## Examples

Valid postcodes:
* 198328
* 310003
* 424000

Invalid postcodes:
* 056879
* 12A483
* 1@63
* 111

Difficulty: EASY
Starter code: def zipvalidate(postcode):
	

Solutions:
def zipvalidate(postcode):
	return len(postcode) == 6 and postcode.isdigit() and (postcode[0] not in '05789')


import re

def zipvalidate(postcode):
	return bool(re.fullmatch('[12346]\\d{5}', postcode))


def zipvalidate(p):
	return p.isdigit() and 100000 < int(p) < 699999 and (p[0] != '5')


def start_digit_valid(func):

	def start_digit_validate(postcode):
		if postcode[0] in '05789':
			return False
		return func(postcode)
	return start_digit_validate

def length_valid(func):

	def length_validator(postcode):
		MANDITORY_LENGTH = 6
		if len(postcode) != MANDITORY_LENGTH:
			return False
		return func(postcode)
	return length_validator

def only_numbers(func):

	def only_numbers(postcode):
		if any([c not in '0123456789' for c in postcode]):
			return False
		return func(postcode)
	return only_numbers

@only_numbers
@length_valid
@start_digit_valid
def zipvalidate(postcode):
	return True


def zipvalidate(postcode):
	try:
		int(postcode)
		if postcode[0] not in ['0', '5', '7', '8', '9'] and len(postcode) == 6:
			return True
	except:
		pass
	return False


zipvalidate = lambda postcode: bool(__import__('re').match('^[12346]\\d{5}\\Z', postcode))


REGEX = __import__('re').compile('[1-46]\\d{5}').fullmatch

def zipvalidate(postcode):
	return bool(REGEX(postcode))


def zipvalidate(p):
	return len(p) == 6 and p[0] in '12346' and all((d in '0123456789' for d in p))


import re

def zipvalidate(postcode):
	return bool(re.fullmatch('[1-46]\\d{5}', postcode))


def zipvalidate(postcode):
	try:
		int(postcode)
	except ValueError:
		return False
	if len(postcode) != 6:
		return False
	return all([x != postcode[0] for x in ['0', '5', '7', '8', '9']])