import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[] score=new int[7];
        while(sc.hasNext())
        {
            for(int i=0;i<7;i++)
            {
                score[i]=sc.nextInt();
            }
            Arrays.sort(score);
            double average=(score[1]+score[2]+score[3]+score[4]+score[5])/5.0;
            System.out.printf("%.2f\n",average);
        }
    }
}