There are 4 white ping-pong balls and 6 yellow ping-pong balls of the same material in the bag. Take at least a few ping-pong balls to ensure that there are balls of both colors. how many
袋子里装有材质相同的白色乒乓球4个，黄色乒乓球6个，至少拿出几个乒乓球才能保证两种颜色的球都有．多少个
<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<result>7</result>