There are 2 red balls, 4 white balls, 5 yellow balls, and 7 green balls in a bag. How many times do you have to touch them to ensure that you touch the same color balls? how many times
一只袋子里有红球2个，白球4个，黄球5个，绿球7个，请问要你摸几次才能保证摸到相同颜色的球？多少次
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>