There are 16 white balls, 4 yellow balls and 6 black balls in the pocket. Please close your eyes and touch the ball from your pocket, at least how many balls you take out to ensure that there are yellow balls in the taken out balls.
口袋中有16个白球，4个黄球，6个黑球．请你闭上眼睛从口袋中摸球，至少取出多少个球，才能保证取出的球有黄球．
<gadget id="calculator">16 + 6 + 1</gadget>
<output>23</output>

<result>23</result>