At least 5 yuan is required to park in a parking lot. If you park for more than 2 hours, you need to pay 0.5 yuan for each additional hour. Less than 1 hour is counted as 1 hour. The car paid 7 yuan when it left the parking lot. How many hours does the car park at most?
在一个停车场停车一次至少要交费5元，如果停车超过2小时，每多停1小时要多交0.5元，不足1小时按1小时算．这辆汽车在离开停车场时交了7元，汽车最多停了几个小时？
<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">2 / 0.5</gadget>
<output>4</output>

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<result>6</result>