There are 36 seats in a row of chairs, and some of the seats are already occupied. When Xiao Ming came to see, no matter which seat he sat in, he would always be adjacent to the seated person. How many people are at least seated before Xiao Ming?
一排椅子共有36个座位，部分座位已有人就座，小明来后一看，他无论坐在哪个座位，都将与已就座的人相邻．在小明之前已就座的最少有多少人．
<gadget id="calculator">36 / 3</gadget>
<output>12</output>

<gadget id="calculator">12 * 1</gadget>
<output>12</output>

<result>12</result>