In the rope skipping exercise, how many times should you jump at least in 1 minute to ensure that you can jump at least 2 times in a certain 1 second.
跳绳练习中，1分钟至少跳多少下，才能保证某1秒钟内至少跳了2下．
<gadget id="calculator">2 * 60</gadget>
<output>120</output>

<result>120</result>