certain class conducts formation queue training, and it happens to be arranged in three rows with equal numbers of people. Xiao Ming is in the middle row, and he is the 8th from the front or the back. How many students are there in the class?
某班进行队形队列训练，正好排成人数相等的三列，小明排在正中一列，从前或从后数都是第8个，全班学生有多少人．
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">16 - 1</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>