On Sunday, Xiaohong does housework at home. It takes 15 minutes to mop the floor, 5 minutes to wipe the furniture, 3 minutes to make the bed, and 20 minutes to boil the water. How many minutes does it take Xiaohong to finish these chores?
星期天，小红在家做家务，拖地板用15分钟，擦家具用5分钟，整理床铺用3分钟，烧开水用20分钟，小红做完这些家务至少用多少分钟．
<gadget id="calculator">20 + 3</gadget>
<output>23</output>

<result>23</result>