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

using namespace std;

int main() {
    vector<int> v;
    
    int tmp;
    for (int i = 0; i < 6; i++) {
        cin >> tmp;
        v.push_back(tmp);
    }
    
    sort(v.begin(), v.end(), greater<int>());
    
    float avg = (v[1] + v[2] + v[3] + v[4]) / 4.0; 
    
    cout << fixed << setprecision(2) << avg << endl;
    
    return 0;
}