There are 35 wooden balls of the same size in a cloth bag, among which there are 10 white, yellow and red balls, 3 blue balls and 2 green balls, how many balls can be taken out at a time to get Make sure that at least 4 of the balls drawn are of the same color.
一个布袋中有35个同样大小的木球，其中白、黄、红三种颜色球各有10个，另外还有3个蓝色球、2个绿色球，试问一次至少取出多少个球，才能保证取出的球中至少有4个是同一颜色的球．
<gadget id="calculator">3 + 2 + 3 + 3 + 3</gadget>
<output>14</output>

<gadget id="calculator">14 + 1</gadget>
<output>15</output>

<result>15</result>