There are 10 red, yellow, and blue socks each. Close your eyes and take out any socks so that there are at least 2 pairs of socks of different colors. Then at least how many socks need to be taken.
有红、黄、蓝袜子各10只，闭着眼睛，任意取出袜子来，使得至少有2双袜子不同色，那么至少需要取多少只袜子．
<gadget id="calculator">10 + 2 + 1</gadget>
<output>13</output>

<result>13</result>