red balls and 4 yellow balls are placed in an opaque plastic bag. Every time you touch a ball from the bag, you must ensure that you touch the red ball, at least how many times you need to touch it.
一个不透明的塑料袋里放3个红球和4个黄球．每次从袋中摸一个球，要保证一定摸到红球，至少要摸多少次．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>