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

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    }

    private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    }

    private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    }
} Main public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    } main {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Integer N = Integer.parseInt(sc.nextLine()); N Integer.parseInt(sc.nextLine()) Integer.parseInt Integer sc.nextLine() sc.nextLine sc String[] VN = sc.nextLine().split(" "); VN sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " int[] values = new int[N]; values new int[N] N for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            values[i] = Integer.parseInt(VN[i]);
        } {
            values[i] = Integer.parseInt(VN[i]);
        } values[i] = Integer.parseInt(VN[i]) values[i] values i Integer.parseInt(VN[i]) Integer.parseInt Integer VN[i] VN i Arrays.sort(values) Arrays.sort Arrays values double ans = mix(values, N); ans mix(values, N) mix values N System.out.println(ans) System.out.println System.out System System.out ans String[] args args private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    } mix {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    } double tmp = values[0]; tmp values[0] values 0 for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        } int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
            double v = values[i];

            tmp = (tmp + v) / 2;
        } {
            double v = values[i];

            tmp = (tmp + v) / 2;
        } double v = values[i]; v values[i] values i tmp = (tmp + v) / 2 tmp (tmp + v) / 2 (tmp + v) tmp v 2 return tmp; tmp int[] values values int N N public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    }

    private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    }
} public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    }

    private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        Integer N = Integer.parseInt(sc.nextLine());
        String[] VN = sc.nextLine().split(" ");

        int[] values = new int[N];
        for (int i = 0; i < N; i++) {
            values[i] = Integer.parseInt(VN[i]);
        }

        Arrays.sort(values);

        // 貪欲法で解いていく
        double ans = mix(values, N);
        System.out.println(ans);
    }

    private static double mix(int[] values, int N) {

        double tmp = values[0];
        for (int i = 1; i < N; i++) {
            double v = values[i];

            tmp = (tmp + v) / 2;
        }
        return tmp;
    }
}
