Put 10 balls of each of the five colors of red, yellow, blue, white, and black into a bag. There must be two balls of the same color if you want to draw out, at least how many balls must be drawn out to ensure that you can get out.
把红、黄、蓝、白、黑五种颜色的球各10个放到一个袋子里．要想摸出的球一定有两个颜色相同，至少要摸出多少个球才能保证摸出．
<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<result>6</result>