Put 10 red, yellow, blue, and white balls in a bag, at least how many balls must be taken out to ensure that 3 balls of the same color are taken.
把红、黄、蓝、白四种球各10个放在一个袋子里，至少要取出多少个个球才能保证取到3个颜色相同的球．
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>