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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 arrow_get(string):
    '''this function exists because ICS uses ISO 8601 without dashes or
    colons, i.e. not ISO 8601 at all.'''

    # replace slashes with dashes
    if '/' in string:
        string = string.replace('/', '-')

    # if string contains dashes, assume it to be proper ISO 8601
    if '-' in string:
        return arrow.get(string)

    string = string.rstrip('Z')
    return arrow.get(string, DATE_FORMATS[len(string)])