From 11 to 20, what is the difference between the sum of all prime numbers and composite numbers?
从11至20中，所有质数与合数的和相差多少．
<gadget id="calculator">12 + 14 + 15 + 16 + 18 + 20</gadget>
<output>95</output>

<gadget id="calculator">11 + 13 + 17 + 19</gadget>
<output>60</output>

<gadget id="calculator">95 - 60</gadget>
<output>35</output>

<result>35</result>