In a calligraphy competition held by all grades of the Experimental Primary School, 20 students from the fourth and fifth grades won prizes. Among the winners, 16 were not in the fourth grade, and 12 were not in the fifth grade. What is the total number of winners of the calligraphy competition in this school?
实验小学各年级都参加的一次书法比赛中，四年级与五年级共有20人获奖，在获奖者中有16人不是四年级的，有12人不是五年级的．该校书法比赛获奖的总人数是多少人．
<gadget id="calculator">20 + 16 + 12</gadget>
<output>48</output>

<gadget id="calculator">48 / 2</gadget>
<output>24</output>

<result>24</result>