production team in a factory processes a batch of parts. When each worker works in his original position, he can complete the production task in 9 hours. If the positions of workers A and B are exchanged, the task can be completed 1 hour earlier when the work efficiency of other workers remains unchanged; if the positions of workers C and D are exchanged, the task can be completed 1 hour earlier when the production efficiency of other workers remains the same ． Question: If the jobs of A and B, C and D are exchanged at the same time, how many minutes can this production task be completed in advance when the work efficiency of other workers remains unchanged?
某工厂的一个生产小组加工一批零件，当每个工人在自己原岗位工作时，9小时可完成这项生产任务．如果交换工人A和B的工作岗位，其他工人工作效率不变时，可提前1小时完成任务；如果交换工人C和D的工作岗位，其他工人生产效率不变时，也可提前1小时完成任务．问：如果同时交换A与B，C与D的工作岗位，其他工人工作效率不变时，可以提前多少分钟完成这项生产任务？
<result>108</result>