In the rope skipping competition, Xiaohong shook hands with everyone participating in the competition once, a total of 39 handshakes, how many people participated in the rope skipping competition?
跳绳比赛中，小红和参加比赛的每个人握一次手，一共握了39次，参加跳绳比赛的一共有多少人？
<gadget id="calculator">39 + 1</gadget>
<output>40</output>

<result>40</result>