When a student calculates X-543, he mistakenly regards 543 as 345, and the difference is 500, so what is the correct answer?
某同学在计算X一543时，把543错误地当作345，所得的差是500，那么，正确答案应该是多少．
<gadget id="calculator">543 - 345</gadget>
<output>198</output>

<gadget id="calculator">500 - 198</gadget>
<output>302</output>

<result>302</result>