The school organized 40 students to clean the nursing home. Among them, 23 cleaned the glass, 25 cleaned the room, 11 did both, and the rest cleaned the yard. How many people cleaned the yard?
学校组织40个学生到敬老院打扫卫生，其中有23人擦玻璃，25人收拾房间，有11人两样活都干了，剩下的人扫院子，扫院子的有多少人？
<gadget id="calculator">25 - 11</gadget>
<output>14</output>

<gadget id="calculator">23 + 14</gadget>
<output>37</output>

<gadget id="calculator">40 - 37</gadget>
<output>3</output>

<result>3</result>