There is a sports field runway. It is known that the runway is 100 meters long, the distance between the outer track and the inner track is 5 meters, and the diameter of the two inner semicircles is 30 meters. Races on such a track have to go through a curve and have the same end point, so how far apart should the starting points of the two be to be fair?
有一个运动场跑道，已知跑道长100米，外道与内道的距离是5米，两个内半圆的直径是30米，现在问，笑笑跑内道，淘淘跑外道，两个人要在这样的跑道上比赛，要经过一个弯道，终点一样，那么两人的起跑点要相距多远才公平？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">30 + 10</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">3.14 * 15</gadget>
<output>47.1</output>

<gadget id="calculator">62.8 - 47.1</gadget>
<output>15.7</output>

<result>15.7</result>