There are three questions A, B, and C in a competition. There are 25 people who get at least one of them right. Among them, 10 people get A right, 13 people get B right, and 15 people get C right. Only three people get all three questions right. 1 person, so how many people only get one question wrong.
一次竞赛共有A、B、C三道题，有25人至少做对了一道，其中做对A的10人，做对B的13人，做对C的15人，三道题都对的仅1人，那么只错一题的有多少人．
<gadget id="calculator">10 + 13 + 15</gadget>
<output>38</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">38 - 2 - 25</gadget>
<output>11</output>

<gadget id="calculator">11 + 1</gadget>
<output>12</output>

<result>12</result>