1.8 yuan per ton within 12 tons, 2 yuan per ton between 12 tons and 20 tons, 3.8 yuan per ton for more than 20 tons, the small owner uses 25 tons of water this month, how much is the water fee?
12吨以内每吨1.8元，12吨到20吨，每吨2元，超过20吨部分，每吨3.8元，小东家本月用水25吨，应缴水费多少钱？
<gadget id="calculator">25 - 20</gadget>
<output>5</output>

<gadget id="calculator">5 * 3.8</gadget>
<output>19</output>

<gadget id="calculator">20 - 12</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">1.8 * 12</gadget>
<output>21.6</output>

<gadget id="calculator">19 + 16 + 21.6</gadget>
<output>56.6</output>

<result>56.6</result>