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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 tag_arxiv(line):
 """Tag arxiv report numbers We handle arXiv in 2 ways: * starting with arXiv:1022.1111 * this format exactly 9999.9999 We also format the output to the standard arxiv notation: * arXiv:2007.12.1111 * arXiv:2007.12.1111v2 """

    def tagger(match):
        groups = match.groupdict()
        if match.group('suffix'):
            groups['suffix'] = ' ' + groups['suffix']
        else:
            groups['suffix'] = ''
        return u'<cds.REPORTNUMBER>arXiv:%(year)s'\
            u'%(month)s.%(num)s%(suffix)s' \
            u'</cds.REPORTNUMBER>' % groups

    line = re_arxiv_5digits.sub(tagger, line)
    line = re_arxiv.sub(tagger, line)
    line = re_new_arxiv_5digits.sub(tagger, line)
    line = re_new_arxiv.sub(tagger, line)
    return line