There are 10 bingbing balls in each of the four colors of red, yellow, blue, and white. Put them in an opaque bag, and at least touch out as many balls as you can to ensure that you can touch two balls of the same color.
有红、黄、蓝、白四种颜色的兵兵球各10个，把它们放到一个不透明的袋子里，至少摸出多少球，可以保证摸到两个颜色相同的球．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>