There are five stations A, B, C, D, and E on a road in sequence. Among the ten distances between any pair of them, only one is unknown K, and the other nine distances are arranged in descending order: 2, 4, 5, 7, 8, 13, 15, 17, 19 (kilometers). When the car from A to E arrives at station C, it is found that the journey has exceeded half of the journey. Then, how many kilometers has the car driven at this time?
一条公路上依次设有A、B、C、D、E五个车站．它们两两之间的十个距离中，只有一个是未知数K，其余九个距离数从小到大排列依次是：2、4、5、7、8、13、15、17、19(公里)．从A开往E的汽车到达C站时发现行程已超过全程的一半，那么，这时汽车开了多少公里．
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