The students went to the amusement park, everyone played the entertainment items, 32 people played the bumper car, 36 people played the rapids, and 21 people played both. How many students went to the amusement park?
同学们去游乐园游玩，每个人都玩了娱乐项目，有32人玩了碰碰车，有36人玩了激流勇进，两项都玩的有21人．去游乐园玩的同学一共有多少人？
<gadget id="calculator">36 - 21</gadget>
<output>15</output>

<gadget id="calculator">32 + 15</gadget>
<output>47</output>

<result>47</result>