There is a basket of eggs, half of which is taken out for the first time and there is one more; the remaining half is taken out for the second time and there are three less, so there are still 20 eggs in the basket. How many eggs are there in the basket?
有一篮鸡蛋，第一次取出全部的一半还多1个；第二次取出余下的一半少3个，这时篮子里还剩下20个鸡蛋．篮子里原有鸡蛋多少个．
<gadget id="calculator">20 - 3</gadget>
<output>17</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">17 / (1/2)</gadget>
<output>34</output>

<gadget id="calculator">34 + 1</gadget>
<output>35</output>

<gadget id="calculator">35 / (1/2)</gadget>
<output>70</output>

<result>70</result>