Select several different numbers (at least one) from 1, 2, 3, ..., 9 so that their sum is a multiple of 3. How many choices are there?
从1，2，3，…，9中选取若干个互不相同的数字(至少一个)，使得其和是3的倍数，共有多少种选法？
<gadget id="calculator">22 * 8</gadget>
<output>176</output>

<gadget id="calculator">176 - 1</gadget>
<output>175</output>

<result>175</result>