There are 17 people in the Chinese extracurricular group in class 31, 18 people in the math extracurricular group, 6 of them participated in both groups, and 15 people in other groups. How many people are there in class 31?
三1班有17人参加语文课外小组，有18人参加数学课外小组，其中有6人两个小组都参加了，还有15人参加了别的小组，三1班一共有多少人．
<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<gadget id="calculator">17 + 12 + 15</gadget>
<output>44</output>

<result>44</result>