The store shipped a batch of apples, sold all half and half on the first day, sold the remaining half and half on the second day, and sold the remaining half and half on the third day. 20 apples, how many apples did the store originally ship?
商店运来一批苹果，第一天卖了全部的一半又半个，第二天卖了余下的一半又半个，第三天卖了第二次余下的一半又半个，这时还剩20个苹果，商店原来运来多少个苹果？
<gadget id="calculator">83 + 0.5</gadget>
<output>83.5</output>

<gadget id="calculator">83.5 * 2</gadget>
<output>167</output>

<result>167</result>