There are 18 girls in the school's science and technology group, and the number of boys is five times less than that of girls. How many boys are there in the school's science and technology group?
学校科技组有女生18人，男生人数比女生的2倍少5人，学校科技组有男生多少人？
<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">36 - 5</gadget>
<output>31</output>

<result>31</result>