There are 36 boys in class 31, 20 boys love to play basketball, 26 boys love to play football, and there is no one who doesn't like to play. How many boys in total love to play both basketball and football?
三1班有36名男生，有20名男生爱打篮球，有26名男生爱踢足球，没有不爱打球的人．一共有几名男生既爱打篮球又爱踢足球？
<gadget id="calculator">26 - 36</gadget>
<output>-10</output>

<gadget id="calculator">20 + (-10)</gadget>
<output>10</output>

<result>10</result>