There are 8 red, green, yellow, and white balls in a cloth bag. Each time a ball is taken out of the cloth bag, the minimum number of balls must be taken out to ensure that there are at least 2 balls of different colors.
一个布袋里有红、绿、黄、白小球各8个，每次从布袋里拿出一个球，最少要拿出多少个小球，才能保证其中至少有2个颜色不同的小球．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>