The school organizes a car model competition. There were 26 participants in the third grade, twice as many participants in the fourth grade as in the third grade, and half of the total number of participants in the fifth grade. How many people in the fifth grade participate in the car model competition?
学校组织车模比赛．三年级有26人参加，四年级参加的人数是三年级的2倍，五年级参加的人数是三、四年级参加的总人数的一半．五年级有多少人参加车模比赛？
<result>34</result>