Grandpa Zhang starts working at 7:00 in the morning, finishes work at 5:00 in the evening, and takes a 2-hour break at noon. How long does Grandpa Zhang have to work in a day?
张爷爷早晨7：00开始劳动，晚上5：00收工，中午休息2小时，张爷爷一天要劳动多长时间？
<gadget id="calculator">17 - 7 - 2</gadget>
<output>8</output>

<result>8</result>