When a number is divided by 3, the remainder is 1; when divided by 5, the remainder is 3; when divided by 7, the remainder is 5; when divided by 9, the remainder is 7. What is the smallest number?
一个数除以3余1，除以5余3，除以7余5，除以9余7，这个数最小是多少．
<gadget id="calculator">5 * 7 * 9</gadget>
<output>315</output>

<gadget id="calculator">315 - 2</gadget>
<output>313</output>

<result>313</result>