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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 _ssweek_year_start(ssweek_year):
    "The gregorian calendar date of the first day of the given Sundaystarting-week year"
    fifth_jan = dt.date(ssweek_year, 1, 5)
    delta = dt.timedelta(fifth_jan.weekday()+1)
    return fifth_jan - delta