The second grade students participate in the summer camp. There are 20 people in the first class, 28 people in the second class, and 45 people in the third class. How many people participated in the summer camp?
二年级同学参加夏令营，一班有20人参加，二班有28人参加，三班有45人参加，参加夏令营的一共有多少人？
<gadget id="calculator">20 + 28 + 45</gadget>
<output>93</output>

<result>93</result>