A piece of wood is 9 meters long, and it takes 1 minute to saw it once, how many minutes will it take to saw it into 4 sections?
一根木材长9米，锯一次需要1分钟，现在锯成4段，需要多少分钟．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<result>3</result>