The monkey mother teaches the little monkey to climb the pole. When it climbs to the top, the monkey mother rewards the little monkey with 8 peaches. The little monkey climbed 18 times and got 53 peaches. How many times did the little monkey fail to reach the top?
猴妈妈教小猴爬杆，爬到顶端猴妈妈奖给小猴8个桃子，爬不到顶端小猴退给猴妈妈5个桃子．小猴一共爬了18次，得到53个桃子．小猴有多少次没有爬到顶端？
<gadget id="calculator">5 * 18</gadget>
<output>90</output>

<gadget id="calculator">90 + 53</gadget>
<output>143</output>

<gadget id="calculator">8 + 5</gadget>
<output>13</output>

<gadget id="calculator">143 / 13</gadget>
<output>11</output>

<result>11</result>