If a log is sawed into 3 sections, how many circular faces are added in total?
一根圆木锯成3段，一共增加了多少个圆形面．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>