Bake pancakes on 1 pan, only put 2 pancakes at the same time, and bake both sides of the pancake for 1 minute. If you want to bake 7 cakes, how many minutes will it take at least?
在1只平底锅上烙薄饼，同时只能放下2只薄饼，饼的两面都要烙1分钟．如果要烙7只饼，至少要用多少分钟．
<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<gadget id="calculator">2 + 2 + 3</gadget>
<output>7</output>

<result>7</result>