Bake a cake on the stove. Both sides of the cake need to be baked. It takes 2 minutes to bake each side. Only 2 cakes can be placed on the stove at the same time. Now you need to bake 6 cakes, how many minutes will it take at least.
在火炉上烤饼，饼的两面都要烤，每烤一面需要2分钟，炉上只能同时放2张饼．现在需要烤6张饼，至少需要多少分钟．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>