The school held a broadcasting exercise competition. The third graders lined up in 15 columns. Each column had an equal number of people. Xiaohong ranked fifth from the front and eighth from the back. How many third graders are there in total?
学校进行广播操比赛，三年级排成15个纵队，每个纵队人数相等，小红从前面数下去排在第5个，从后面数上来排在第8个，三年级一共有多少个人？
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">12 * 15</gadget>
<output>180</output>

<result>180</result>