There are 8 socks of each of the four colors of red, yellow, blue, and black mixed together. If you are asked to close your eyes, how many socks should you take out at least each time to ensure that there must be 2 socks of the same color.
有红、黄、蓝、黑四种颜色的袜子各8只混在一起，如果让你闭上眼睛，每次至少拿出多少只才能保证一定有2只同色的袜子．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>