import java.util.*;

class Main {
    final Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    private void run() {
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);

        for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        }
        System.out.println(v[n-1]);
    }
}
 import java.util.*; util.* java class Main {
    final Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    private void run() {
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);

        for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        }
        System.out.println(v[n-1]);
    }
} Main final Scanner sc = new Scanner(System.in); sc new Scanner(System.in) public static void main(String[] args) {
        new Main().run();
    } main {
        new Main().run();
    } new Main().run() new Main().run new Main() String[] args args private void run() {
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);

        for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        }
        System.out.println(v[n-1]);
    } run {
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);

        for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        }
        System.out.println(v[n-1]);
    } int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc double[] v = new double[n]; v new double[n] n for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            v[i] = sc.nextDouble();
        } {
            v[i] = sc.nextDouble();
        } v[i] = sc.nextDouble() v[i] v i sc.nextDouble() sc.nextDouble sc Arrays.sort(v) Arrays.sort Arrays v for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        } {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        } v[i] = (v[i] + v[i - 1]) / 2 v[i] v i (v[i] + v[i - 1]) / 2 (v[i] + v[i - 1]) v[i] v i v[i - 1] v i - 1 i 1 2 v[i - 1] = 0 v[i - 1] v i - 1 i 1 0 System.out.println(v[n-1]) System.out.println System.out System System.out v[n-1] v n-1 n 1
import java.util.*;

class Main {
    final Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    private void run() {
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);

        for (int i = 1; i < n; i++) {
            v[i] = (v[i] + v[i - 1]) / 2;
            v[i - 1] = 0;
        }
        System.out.println(v[n-1]);
    }
}

