Mom bought less than 30 apples, 5 apples with 5 lands, and one less in the end;
妈妈买回不到30个的苹果，5个5个地数，最后少1个；6个6个地数，最后也少1个，你说妈妈买了多少个苹果．
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">30 - 1</gadget>
<output>29</output>

<result>29</result>