There is a box containing 10 pairs of black socks and 10 pairs of white socks. They are all scattered in the box. If you want to find a pair of socks of the same color from the box without looking at the color, how many socks do you need to find at least? to meet the requirements?
有一只箱子里装有10双黑色的袜子和10双白色的袜子，它们都散放在箱子里，如果不看颜色而要从箱子里摸出颜色相同的一双袜子，至少需要摸出多少只袜子才能符合要求？
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<result>3</result>