import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		double a, b, c, d, e, f, min, max;
		a = sc.nextDouble();
		min = a;
		max = a;
		b = sc.nextDouble();
		min = Math.min(min, b);
		max = Math.max(max, b);
		c = sc.nextDouble();
		min = Math.min(min, c);
		max = Math.max(max, c);
		d = sc.nextDouble();
		min = Math.min(min, d);
		max = Math.max(max, d);
		e = sc.nextDouble();
		min = Math.min(min, e);
		max = Math.max(max, e);
		f = sc.nextDouble();
		min = Math.min(min, f);
		max = Math.max(max, f);
		System.out.println((a + b + c + d + e + f - min - max) / 4);
	}
}