def squid_to_guid(squid):
    '''
    Converts a compressed GUID (SQUID) back into a GUID

    Args:

        squid (str): A valid compressed GUID

    Returns:
        str: A valid GUID
    '''
    squid_pattern = re.compile(r'^(\w{8})(\w{4})(\w{4})(\w\w)(\w\w)(\w\w)(\w\w)(\w\w)(\w\w)(\w\w)(\w\w)$')
    squid_match = squid_pattern.match(squid)
    guid = ''
    if squid_match is not None:
        guid = '{' + \
               squid_match.group(1)[::-1]+'-' + \
               squid_match.group(2)[::-1]+'-' + \
               squid_match.group(3)[::-1]+'-' + \
               squid_match.group(4)[::-1]+squid_match.group(5)[::-1] + '-'
        for index in range(6, 12):
            guid += squid_match.group(index)[::-1]
        guid += '}'
    return guid