The students lined up neatly to participate in the gymnastics performance. There are 6 people in front of Jiang Xin, 11 people in the back, 4 people on the left and 5 people on the right. How many people participated in the gymnastics performance?
同学们排成整齐的队列参加体操表演．蒋欣的前面有6人，后面有11人，左面有4人，右面有5人．参加体操表演的共有多少人．
<gadget id="calculator">4 + 1 + 5</gadget>
<output>10</output>

<gadget id="calculator">6 + 1 + 11</gadget>
<output>18</output>

<gadget id="calculator">10 * 18</gadget>
<output>180</output>

<result>180</result>