The distance between A and B is several kilometers. A starts from A, and B and C start from B at the same time and walk toward each other. A and C meet at point C. After meeting, they continue to move forward. After C arrives at A Go back immediately and meet B again at point C. It is known that A and B have the same speed, AC is 6 kilometers apart, what is the distance between A and B?
A、B两地相距若干千米，甲从A地，乙、丙从B地同时出发，相向而行，甲、丙两人在C点相遇，相遇后两人继续前进，丙到A地后立即返回，在C点又与乙相遇，已知甲、乙速度相同，AC相距6千米，A、B两地的距离是多少？
<result>18</result>