There are 8 red balls, 7 yellow balls and 6 blue balls in a box. Close your eyes to touch the ball, at least how many balls must be touched to ensure that there are 6 balls of the same color.
在一个箱子里有8只红球，7只黄球，6只蓝球．闭着眼去摸球，至少要摸出多少个球才能保证有6个同色的球．
<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<result>16</result>