The school celebrates the "June. 1st" party and needs to move 12 tables. Each teacher carries one, and two classmates carry one. Now there are 5 teachers, how many students are needed to move at once?
学校开庆"六．一"联欢会，要搬12张桌子．每个老师搬一张，两个同学抬一张．现在有5个老师，还要多少个同学才能一次搬完？
<gadget id="calculator">12 - 5</gadget>
<output>7</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>