A pan can only bake two cakes at the same time, and it takes 2 minutes to cook one side of the cakes. How long does it take to cook five cakes at least?
一只平底锅，只能同时烙两张饼，烙熟饼的一面要2分钟，要烙熟5张饼最少需要多少分钟．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

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

<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<result>10</result>