#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>

int main() {
    int n;
    std::cin >> n;
    std::vector<int> scores(n);
    for (int i = 0; i < n; ++i) {
        std::cin >> scores[i];
    }
    // 对成绩进行降序排序
    std::sort(scores.begin(), scores.end(), std::greater<int>());
    double sum = 0;
    // 计算前5名成绩的总和
    for (int i = 0; i < 5; ++i) {
        sum += scores[i];
    }
    // 计算平均分
    double average = sum / 5;
    // 输出结果，保留1位小数
    std::cout << std::fixed << std::setprecision(1) << average << std::endl;
    return 0;
}    
/**************************************************************
	Problem: 1221
	User: fuyijun
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/