A and B run in opposite directions around a circular track at a constant speed, starting from the two endpoints of the diameter. If they start at the same time and meet for the first time when B finishes running 100 meters, and meet for the second time when A runs a circle with 60 meters left, what is the length of the runway in meters?
甲、乙两人以匀速绕圆形跑道按相反方向跑步，出发点在直径的两个端点．如果他们同时出发，并在乙跑完100米时第一次相遇，甲跑一圈还差60米时第二次相遇，那么跑道的长是多少米．
<gadget id="calculator">100 * 3</gadget>
<output>300</output>

<gadget id="calculator">300 - 60</gadget>
<output>240</output>

<gadget id="calculator">240 * 2</gadget>
<output>480</output>

<result>480</result>