A workshop planned to produce 4,800 auto parts in 15 days, but 1,200 were produced in 3 days. According to this calculation, how many days can it be completed in advance?
某车间计划15天生产4800个汽车零件，结果3天就生产了1200个，照这样计算，可以提前几天完成？
<gadget id="calculator">1_200 / 3</gadget>
<output>400</output>

<gadget id="calculator">4_800 / 400</gadget>
<output>12</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<result>3</result>