Xiaodong goes to bed at 10:00 every night and wakes up at 7:00 in the morning, how many hours does he sleep every day?
小冬每天晚上10：00睡觉，早上7：00起床，他每天睡多少时．
<gadget id="calculator">2 + 7</gadget>
<output>9</output>

<result>9</result>