store has such a rule: After drinking soda, you can exchange 5 empty soda bottles for 1 bottle of soda. Aunt Wang bought 20 bottles of soda, how many bottles of soda can she actually drink?
一个商店有这样一条规定：喝完汽水后，用5个空汽水瓶可以换1瓶汽水．王阿姨买了20瓶汽水，实际可以喝多少瓶汽水．
<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<gadget id="calculator">24 + 1</gadget>
<output>25</output>

<result>25</result>