There are 5 red and 5 yellow balls of the same size in a box. There must be 2 balls of the same color to be drawn, at least how many balls must be drawn.
箱子里有同样大小的红球和黄球各5个．要想摸出的球一定有2个同色，至少要摸出多少个球．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<result>3</result>