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

public class Main {

    void solve() {
        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;
        }
        System.out.print(ans);
    }

    // Main
    public static void main(String[] args) {
        new Main().solve();
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    void solve() {
        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;
        }
        System.out.print(ans);
    }

    // Main
    public static void main(String[] args) {
        new Main().solve();
    }
} Main void solve() {
        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;
        }
        System.out.print(ans);
    } solve {
        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;
        }
        System.out.print(ans);
    } 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;
        } int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
            ans = (double)(ans + v[i]) / 2;
        } {
            ans = (double)(ans + v[i]) / 2;
        } ans = (double)(ans + v[i]) / 2 ans (double)(ans + v[i]) / 2 (double)(ans + v[i]) ans v[i] v i 2 System.out.print(ans) System.out.print System.out System System.out ans // Main
    public static void main(String[] args) {
        new Main().solve();
    } main {
        new Main().solve();
    } new Main().solve() new Main().solve new Main() String[] args args public class Main {

    void solve() {
        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;
        }
        System.out.print(ans);
    }

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

    void solve() {
        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;
        }
        System.out.print(ans);
    }

    // Main
    public static void main(String[] args) {
        new Main().solve();
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    void solve() {
        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;
        }
        System.out.print(ans);
    }

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