☆/△=7…◇, when ◇ is at most 8, what should ☆ be?
☆/△=7…◇，当◇最大是8时，☆应是多少．
<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<gadget id="calculator">7 * 9</gadget>
<output>63</output>

<gadget id="calculator">63 + 8</gadget>
<output>71</output>

<result>71</result>