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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 backwards(apps, schema_editor):
 """ Delete initial recurrence rules. """

    RecurrenceRule = apps.get_model('icekit_events', 'RecurrenceRule')
    descriptions = [d for d, rr in RULES]
    RecurrenceRule.objects.filter(description__in=descriptions).delete()