If there are enough balls of 5 different colors in the cloth bag, how many balls must be taken out at least to ensure that there must be 3 balls of the same color.
布袋中有足够多的5种不同着色的球，最少取出多少个球，才能保证其中一定有3个同色的球．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<result>11</result>