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

public class Main {

    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    }

} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    }

} Main public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    } main {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    } @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] v = new int[n]; v new int[n] n for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        } int i = 0 ; int i = 0 ; i 0 i < n i n i++ i++ i {
            v[i] = sc.nextInt();
        } {
            v[i] = sc.nextInt();
        } v[i] = sc.nextInt() v[i] v i sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v double ans = v[0]; ans v[0] v 0 for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        } int i = 1 ; int i = 1 ; i 1 i < n i n i++ i++ i {
            ans = (double) (ans + v[i]) / 2.0;
        } {
            ans = (double) (ans + v[i]) / 2.0;
        } ans = (double) (ans + v[i]) / 2.0 ans (double) (ans + v[i]) / 2.0 (double) (ans + v[i]) ans v[i] v i 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) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    }

} public class Main {

    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    }

} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for (int i = 0 ; i < n ; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double ans = v[0];
        for (int i = 1 ; i < n ; i++) {
            ans = (double) (ans + v[i]) / 2.0;
        }
        System.out.println(ans);
    }

}