Master Wang uses a pan to bake pancakes, put up to 2 cakes in the pan at a time, and bake both sides. It takes 3 minutes to bake one side, and at least how many minutes to bake three cakes.
王师傅用一个平底锅烙饼，锅里一次最多放2个饼，两面都要烙，烙一面需3分钟，烙三张饼至少需多少分钟．
<gadget id="calculator">3 + 3 + 3</gadget>
<output>9</output>

<result>9</result>