Divide a number by 17, and the quotient is 20 with a remainder of 9. What is this number?
一个数除以17，商20余9，这个数是多少．
<gadget id="calculator">17 * 20</gadget>
<output>340</output>

<gadget id="calculator">340 + 9</gadget>
<output>349</output>

<result>349</result>