import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) 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 < v.length; i++) {
            v[i] = sc.nextDouble();
        } int i = 0; int i = 0; i 0 i < v.length i v.length v v.length 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 double res = v[0]; res v[0] v 0 for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        } int i = 1; int i = 1; i 1 i < v.length i v.length v v.length i++ i++ i {
            res = (res + v[i]) / 2;
        } {
            res = (res + v[i]) / 2;
        } res = (res + v[i]) / 2 res (res + v[i]) / 2 (res + v[i]) res v[i] v i 2 System.out.println(res) System.out.println System.out System System.out res sc.close() sc.close sc String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    }
} Main
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        double[] v = new double[N];
        for (int i = 0; i < v.length; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        double res = v[0];
        for (int i = 1; i < v.length; i++) {
            res = (res + v[i]) / 2;
        }
        System.out.println(res);
        sc.close();
    }
}