It takes 5 minutes to saw a water pipe into 2 sections, how many minutes does it take to saw 5 sections
一根水管锯成2段要5分钟，锯成5段要多少分钟
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>