There are 2 red balls, 3 yellow balls, 4 basketballs and 5 green balls in the box. These balls are all the same except for the color. At least how many balls can be drawn from the box to ensure that there is 1 green ball.
盒子里有2个红球、3个黄球、4个篮球和5个绿球，这些球除颜色外其他均相同，至少从中摸出多少个球，才能保重其中有1个绿球．
<gadget id="calculator">2 + 3 + 4 + 1</gadget>
<output>10</output>

<result>10</result>