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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 simple(self):
        '''A string representation with only one period delimiter.'''
        if self._days:
            return '%sD' % self.totaldays
        elif self.months:
            return '%sM' % self._months
        elif self.years:
            return '%sY' % self.years
        else:
            return ''