A road runs from A to C via B. It is known that the distance between AB and B is 600 meters, and the distance between BC and B is 780 meters. Now planting trees on the side of the road requires that the distance between two adjacent trees be equal, and a tree must be planted at B and the midpoint of AB and BC, then the distance between two adjacent trees is at most How much rice?
一条公路由A地经B地到C地，已知AB之间相距600米，BC之间相距780米．现在路边种树，要求相邻两棵树之间的距离相等，并且在B地以及AB、BC的中点上都要种一棵树，那么相邻的两棵树之间的距离最多是多少米？
<gadget id="calculator">2 * 3 * 5</gadget>
<output>30</output>

<result>30</result>