
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    }
    
} import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.Scanner; Scanner java.util public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    }
    
} Main /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    } main {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    } Scanner s = new Scanner(System.in); s new Scanner(System.in) int n = s.nextInt(); n s.nextInt() s.nextInt s ArrayList<Integer> vs = new ArrayList<>(); vs new ArrayList<>() for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        } int i = 0; int i = 0; i 0 i < n i n i ++ i ++ i {
            vs.add(s.nextInt());
        } {
            vs.add(s.nextInt());
        } vs.add(s.nextInt()) vs.add vs s.nextInt() s.nextInt s Collections.sort(vs) Collections.sort Collections vs double output = vs.get(0); output vs.get(0) vs.get vs 0 for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        } int i = 1; int i = 1; i 1 i < vs.size() i vs.size() vs.size vs i ++ i ++ i {
            output = (double) (output + vs.get(i)) / 2;
        } {
            output = (double) (output + vs.get(i)) / 2;
        } output = (double) (output + vs.get(i)) / 2 output (double) (output + vs.get(i)) / 2 (double) (output + vs.get(i)) output vs.get(i) vs.get vs i 2 System.out.println(output) System.out.println System.out System System.out output String[] args args public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    }
    
} public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    }
    
} Main

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        
        ArrayList<Integer> vs = new ArrayList<>();
        
        for (int i = 0; i < n; i ++) {
            vs.add(s.nextInt());
        }
        
        Collections.sort(vs);
        
        double output = vs.get(0);
        
        for (int i = 1; i < vs.size(); i ++) {
            output = (double) (output + vs.get(i)) / 2;
        }
        
        
        System.out.println(output);
        
    }
    
}
