A letter was taken out of the mailbox at 17:00 yesterday and arrived at the destination at 7:00 today. How many hours did it take for the letter to reach the destination?
一封信昨天17：00从邮箱取出，到今天7：00到达目的地，这封信经过了多少小时到达目的地？
<gadget id="calculator">7 + 7</gadget>
<output>14</output>

<result>14</result>