#include <iostream>
#include <algorithm>
#include <iomanip>
using namespace std;
int main() {
    int score[7];
    while (cin >> score[0] >> score[1] >> score[2] >> score[3] >> score[4] >> score[5] >> score[6]) {
        sort(score, score + 7);
        double sum = score[1] + score[2] + score[3] + score[4] + score[5];
        cout << fixed << setprecision(2) << sum / 5 << endl;
    }
    return 0;
}