The security uncle goes to work at 10 o'clock in the evening and leaves work at 8 o'clock the next morning. How long is the security uncle on duty?
保安叔叔晚上10点上班，第二天早上8点下班，保安叔叔值勤多少时间？
<gadget id="calculator">12 - 10</gadget>
<output>2</output>

<gadget id="calculator">2 + 8</gadget>
<output>10</output>

<result>10</result>