What is the sum of the smallest composite number, the largest prime number, the smallest even number, and the largest odd number within 10.
10以内最小的合数、最大的质数、最小的偶数、最大的奇数之和是多少．
<gadget id="calculator">4 + 7 + 0 + 9</gadget>
<output>20</output>

<result>20</result>