There are 30 red balls, 20 white balls, 15 yellow balls and 25 blue balls in a box. Then at least how many balls must be drawn from the box to ensure that the drawn balls are red balls, white balls, yellow balls and blue balls.
箱子里有红球30个，白球20个，黄球15个，蓝球25个．那么最少要从箱子里摸出多少个球，才能保证摸出的球是红球，白球，黄球和蓝球．
<gadget id="calculator">75 + 1</gadget>
<output>76</output>

<result>76</result>