On one side of the 90-meter-long runway, 10 colored flags are inserted equidistantly (both ends are inserted), and the distance between each two adjacent colored flags is how many meters
在长90米的跑道一侧等距离插上10面彩旗(两端都插)，每相邻两面彩旗之间相距多少米
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">90 / 9</gadget>
<output>10</output>

<result>10</result>