All students in Class 6 and 2 stand in a circle and play games. Count clockwise from Xiaojun. Xiaoqiang is 27th. Count counterclockwise. Xiaoqiang is 20th. How many students are there in this class?
六2班全体同学站成一个圆圈做游戏，从小军数起，按顺时针方向数，小强第27个，按逆时针方向数，小强是第20个，这班有多少名同学．
<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<gadget id="calculator">27 + 18</gadget>
<output>45</output>

<result>45</result>