There are 10 red, white and blue balls in a bag, at least how many balls are taken out to ensure that there are 2 balls of different colors.
一个袋子里有红、白、蓝三种颜色的球各10个，至少拿出多少球才能保证有2个球是不同色的．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<result>11</result>