Put red, blue, green, and white balls into the dark box, and at least how many balls can be drawn out to ensure that there are 3 balls of the same color.
把红、蓝、绿、白四种颜色的小球放入暗箱中，至少摸出多少个小球，才能保证有3个小球的颜色相同．
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>