There are 3 red balls, 7 yellow balls, 8 black balls, and 9 white balls in the pocket, at least how many balls must be taken to ensure that there are 6 balls of the same color.
口袋里有红球3个，黄球7个，黑球8个，白球9个，至少要取多少个小球才能保证有6个小球同色．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">3 + 15 + 1</gadget>
<output>19</output>

<result>19</result>