13 children are playing hide and seek, 3 of them have been caught, how many children have not been caught yet?
13个小朋友在玩捉迷藏的游戏，已经捉到了其中的3个人，藏起来还没有捉到的小朋友有多少个．
<gadget id="calculator">13 - 1 - 3</gadget>
<output>9</output>

<result>9</result>