There are 8 people who clean the windows, 10 people who sweep the floor, and 3 people who do both. How many people work in total?
擦窗户的有8人，扫地的有10人，两样事情都做的有3人，参加劳动的一共有多少人？
<gadget id="calculator">10 - 3</gadget>
<output>7</output>

<gadget id="calculator">8 + 7</gadget>
<output>15</output>

<result>15</result>