There are 8 students in front of Li Ping who are taller than him and 9 students in the back who are shorter than him in a group of elementary school students. How many students are there in this group?
一队小学生，李平前面有8个学生比他高，后面9个学生比他矮，这队小学生共有多少人？
<gadget id="calculator">8 + 1 + 9</gadget>
<output>18</output>

<result>18</result>