There are a bunch of watermelons, the first half of which is taken out is 3 less, the remaining half is taken for the second time and the remaining half is taken for the third time, there are still 5 watermelons, how many are there? watermelon?
有一堆西瓜，第一次取了全部的一半少3个，第二次取了余下的一半多2个，第三次取了余下的一半，这时还有5个西瓜，问原来有几个西瓜？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<gadget id="calculator">24 - 3</gadget>
<output>21</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>