Two elves, A and B, start from A and B respectively at the same time, and walk back and forth between A and B. A's speed remains constant. Every time A and B meet head-on, B will increase its speed to 4 times that before the encounter. The first two encounters between A and B are at a place C between A and B, and when B returns to B for the first time, A is 60 meters away from C. What is the distance between A and B?
甲、乙两只精灵分别同时从A、B出发，在A、B两地间往返行走．甲的速度始终不变．每次甲、乙迎面相遇，乙都将速度提高到相遇前的4倍．甲、乙的前2次迎面相遇都在A、B间的某地C，而当乙第一次回到B时，甲离C地60米．A、B间的路程是多少米．
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / (1/8)</gadget>
<output>8</output>

<gadget id="calculator">60 * 8 * 2</gadget>
<output>960</output>

<gadget id="calculator">60 * 8</gadget>
<output>480</output>

<gadget id="calculator">960 + 480</gadget>
<output>1_440</output>

<result>1_440</result>