There is a three-digit number, subtract the sum of its digits to get 2□1, what is the largest original three-digit number?
有一个三位数，减去它的各位数字的和得到2□1，原来的三位数最大是多少．
<gadget id="calculator">261 + 18</gadget>
<output>279</output>

<result>279</result>