For fried pancakes in the breakfast shop, the oil pan can fry up to 2 pancakes at a time, and it takes 4 minutes to fry one pancake (2 minutes for the front and back sides). If a customer wants 9 pancakes, how soon can the owner of the breakfast shop give the pancakes to him?
早餐店炸油饼，油锅一次最多能炸2张饼，炸熟一张饼要4分钟(正反面各2分钟)．如果一个客人要9张饼，早餐店老板最快多少分钟可以把油饼给他？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

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

<gadget id="calculator">12 + 6</gadget>
<output>18</output>

<result>18</result>