The local call rate in Yancheng City is 2 cents for the first 3 minutes, and 1 cent for each additional minute (less than 1 minute is counted as 1 minute). Mom gave Xiaolin 60 cents to call his grandmother in this city. How many minutes can Xiaolin and grandma talk at most?
盐城市的市话收费标准是前3分钟共2角钱，以后每增加1分钟(不足1分钟按1分钟计算)付1角．妈妈给小林6角钱去打电话给本市的外婆，小林和外婆最多可以通话几分钟？
<gadget id="calculator">2 / 1</gadget>
<output>2</output>

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

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<result>7</result>