There are 283 people in factories A and B, 386 people in factories B and C, and 488 people in factories C and D. How many people are there in Factory A and Factory D?
甲、乙两厂共283人，乙、丙两厂共386人，丙、丁两厂共488人．甲厂和丁厂共有多少人？
<gadget id="calculator">488 - 386</gadget>
<output>102</output>

<gadget id="calculator">283 + 102</gadget>
<output>385</output>

<result>385</result>