It is known that X=P*Q+18, where P and Q are prime numbers within 100, and X is an even number, then what is the maximum value of X.
已知X=P*Q+18，其中P和Q均为100以内的质数，且X是个偶数，那么X的最大值是多少．
<gadget id="calculator">2 * 97</gadget>
<output>194</output>

<gadget id="calculator">194 + 18</gadget>
<output>212</output>

<result>212</result>