The third grade of Donghu Road Primary School held a mathematics competition with a total of 20 questions. 5 points are awarded for a correct answer, and 2 points will be deducted for an incorrect answer or an incorrect answer. Liu Gang scored 86 points, how many questions did he get right?
东湖路小学三年级举行数学竞赛，共20道试题．做对一题得5分，没有做一题或做错一题都要倒扣2分．刘钢得了86分，问他做对了几道题？
<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<gadget id="calculator">100 - 86</gadget>
<output>14</output>

<gadget id="calculator">2 + 5</gadget>
<output>7</output>

<gadget id="calculator">14 / 7</gadget>
<output>2</output>

<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<result>18</result>