There are 90 seats in a row of benches, some of which are already occupied. At this time, another person came to sit on this row of benches. Interestingly, no matter which seat he sat on, he was adjacent to someone who was already seated. It turns out that at least how many people are already seated.
一排长椅共有90个座位，其中一些座位已经有人就座了．这时，又来了一个人要坐在这排长椅上，有趣的是，他无论坐在哪个座位上都与已经就座的某个人相邻．原来至少有多少人已经就座．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">90 * (1/3)</gadget>
<output>30</output>

<result>30</result>