package No300台;

import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		solver();
	}

	static void solver() {
		Scanner sc = new Scanner(System.in);
		double[] s = new double[6];
		double sum = 0;
		for (int i = 0; i < 6; i++) {
			s[i] = sc.nextDouble();
			sum += s[i];
		}
		Arrays.sort(s);
		sum = sum - s[0] - s[5];
		sum = sum /4* 100;
		sum = (int) sum;
		sum = sum / 100;
		System.out.printf("%.2f",sum);
	}
}