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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse_conference_address(address_string):
 """Parse a conference address. This is a pretty dummy address parser. It only extracts country and state (for US) and should be replaced with something better, like Google Geocoding. """


    geo_elements = address_string.split(',')
    city = geo_elements[0]
    country_name = geo_elements[-1].upper().replace('.', '').strip()
    us_state = None
    state = None
    country_code = None

    # Try to match the country
    country_code = match_country_name_to_its_code(country_name, city)

    if country_code == 'US' and len(geo_elements) > 1:
        us_state = match_us_state(geo_elements[-2].upper().strip()
                                  .replace('.', ''))

    if not country_code:
        # Sometimes the country name stores info about U.S. state
        us_state = match_us_state(country_name)

    if us_state:
        state = us_state
        country_code = 'US'

    return {
        'cities': [
            city,
        ],
        'country_code': country_code,
        'postal_code': None,
        'state': state,
    }