There are 4 red pencils and 3 blue pencils in the cloth bag. If you close your eyes and touch, how many pencils must you find at a time to ensure that there is at least one blue pencil.
布袋里有4支红铅笔和3支蓝铅笔，如果闭上眼睛摸，一次必须摸出多少支铅笔才能保证至少有一支蓝铅笔．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>