#include<iostream>
#include<vector>
#include<algorithm>
#include<stdio.h>
using namespace std;
int main() {
	vector<double> score(6);
	double sum=0;
	
	for (int i = 0; i < 6; i++) {
		cin >> score[i];
	}
	sort(score.begin(),score.end());
	score.pop_back();
	score.erase(score.begin()+0);


	for (int i = 0; i < 4 ; i++) {
		sum += score[i];
	}
	printf("%lf", sum / 4);
	return 0;

}