Friendship Garment Factory processed 192 sets of clothes. The original plan was to process 2 sets per person per day, and 8 people could finish it on time. Now it is necessary to complete the task 4 days ahead of schedule. If the daily work efficiency of each person remains the same, how many people are actually required to participate in production?
友谊服装厂加工192套衣服，原计划每人每天加工2套，8人可以按时完成．现在要提前4天完成任务，如果每人每天工作效率不变，实际需要多少人参加生产？
<gadget id="calculator">192 / 2 / 8</gadget>
<output>12</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<result>12</result>