There are 4 small beads of red, yellow, and blue colors mixed in the pocket. In order to ensure that 2 beads of the same color can be taken at a time, how many beads should be taken at a time.
有红、黄、蓝三种颜色的小珠子各4颗混放在口袋里，为了保证一次能取到2颗颜色相同的珠子，一次至少取多少颗．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>