There are 4 balls of different colors in a cloth bag, each with 50 balls. If you close your eyes and take the balls, how many balls should you take out to ensure that 5 of them have the same color.
一个布袋里有4种不同颜色的球，每种各有50个，如果闭上眼睛取球，至少取出多少个球才能保证其中有5个颜色相同．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">16 + 1</gadget>
<output>17</output>

<result>17</result>