There are 5 black balls, 3 white balls and 4 red balls in a pocket, at least how many balls are taken from it to ensure that there are red balls in it.
在一个口袋中有5个黑球、3个白球和4个红球，至少从中取出多少个球，才能保证其中有红球．
<gadget id="calculator">5 + 3 + 1</gadget>
<output>9</output>

<result>9</result>