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

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    }
} Main public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    } main {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = Integer.parseInt(sc.next()); n Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int[] v = new int[n]; v new int[n] n for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            v[i] = Integer.parseInt(sc.next());
        } {
            v[i] = Integer.parseInt(sc.next());
        } v[i] = Integer.parseInt(sc.next()) v[i] v i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc Arrays.sort(v) Arrays.sort Arrays v double result = (double) v[0]; result (double) v[0] v 0 for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            result = (result + v[i]) / 2;
        } {
            result = (result + v[i]) / 2;
        } result = (result + v[i]) / 2 result (result + v[i]) / 2 (result + v[i]) result v[i] v i 2 System.out.println(result) System.out.println System.out System System.out result sc.close() sc.close sc String args[] args public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    }
} public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] v = new int[n];
        for (int i = 0; i < n; i++) {
            v[i] = Integer.parseInt(sc.next());
        }

        // 主処理
        Arrays.sort(v);
        double result = (double) v[0];
        for (int i = 1; i < n; i++) {
            result = (result + v[i]) / 2;
        }

        // 出力
        System.out.println(result);
        sc.close();
    }
}