10 small balls of red, yellow and blue colors are placed in a box, at least how many balls are taken to ensure that 6 balls of the same color are taken.
有红黄蓝三种颜色的小球各10个放到一个盒子里，至少取多少个球才能保证取到6个颜色相同的球．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<result>16</result>