The film crew has a one-day journey from city A to city B, and plans to travel 100 kilometers longer in the morning than in the afternoon to have lunch in city C. Due to road traffic jams, I arrived at a small town at noon, and only traveled one-third of the original plan. After passing the small town, the car drove 400 kilometers and stopped to rest in the evening. The driver said, walk another half of the distance from City C to here, and you will arrive at your destination. What is the distance in miles between A and B?
摄制组从A市到B市有一天的路程，计划上午比下午多走100千米到C市吃午饭．由于道路堵车，中午才赶到一个小镇，只行驶了原计划的三分之一．过了小镇，汽车赶了400千米，傍晚才停下来休息．司机说，再走从C市到这里的二分之一，就到达目的地了．那么A，B两市相距多少千米．
<result>600</result>