Each of the 100 college students knows at least one foreign language, of which 76 know French, 83 know English, 65 know Japanese, 50 know three foreign languages, and how many people know only two foreign languages.
100位大学生中每人至少懂一种外语，其中76人懂法语，83人懂英语，65人懂日语，懂三种外语的有50人，只懂两种外语的有多少人．
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">83 - 100 - 100</gadget>
<output>-117</output>

<gadget id="calculator">76 + 65 + (-117)</gadget>
<output>24</output>

<result>24</result>