

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

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

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

    }
} import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

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

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

    } main {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc ArrayList<Double> arr = new ArrayList<>(); arr new ArrayList<>() for(int i = 0; i < n; i++) arr.add((double) sc.nextInt()); int i = 0; int i = 0; i 0 i < n i n i++ i++ i arr.add((double) sc.nextInt()); arr.add((double) sc.nextInt()) arr.add arr (double) sc.nextInt() sc.nextInt sc sc.close() sc.close sc Collections.sort(arr) Collections.sort Collections arr double ans = arr.get(0); ans arr.get(0) arr.get arr 0 for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        } int i = 1; int i = 1; i 1 i < arr.size() i arr.size() arr.size arr i++ i++ i {
            ans = (arr.get(i) + ans) / 2.0;
        } {
            ans = (arr.get(i) + ans) / 2.0;
        } ans = (arr.get(i) + ans) / 2.0 ans (arr.get(i) + ans) / 2.0 (arr.get(i) + ans) arr.get(i) arr.get arr i ans 2.0 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

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

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

    }
} Main


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

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

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Double> arr = new ArrayList<>();
        for(int i = 0; i < n; i++) arr.add((double) sc.nextInt());
        sc.close();

        Collections.sort(arr);
        double ans = arr.get(0);

        for(int i = 1; i < arr.size(); i++){
            ans = (arr.get(i) + ans) / 2.0;
        }

        System.out.println(ans);

    }
}
