There are 10 small balls of red, yellow, green, and white in the pocket. It is required to close the eyes to ensure that no less than 5 balls of the same color are drawn at one time. At least how many balls need to be drawn at one time.
口袋里放有红、黄、绿、白四种颜色的小球各10个，要求闭着眼睛保证一次摸出不小于5个同色的球，需要一次摸出至少多少个球．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">16 + 1</gadget>
<output>17</output>

<result>17</result>