The elder brother's age is the smallest prime number among the two digits, and the father's age is 5 years less than four times the elder brother's age. How old is the father?
哥哥的年龄是两位数中最小的质数，爸爸的年龄比哥哥的年龄的4倍少5岁，爸爸多少岁？
<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">44 - 5</gadget>
<output>39</output>

<result>39</result>