Xiaoliang uses a frying pan to bake flatbreads. There can be at most 2 flatbreads in the pan at the same time, and it takes 4 minutes to bake 1 flatbread (2 minutes for each side). How many minutes did it take Xiaoliang to bake 5 flatbreads at least.
小亮用平底锅烙大饼，锅内同时最多能放2张大饼，而烙1张大饼需要4分钟(每面各需烙2分钟)．小亮烙了5张大饼至少用了多少分钟．
<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>