import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    }
} import java.math.BigDecimal; BigDecimal java.math import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    }
} Main public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    } main {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    } java.util.Scanner input = new Scanner(System.in); input new Scanner(System.in) int n = input.nextInt(); n input.nextInt() input.nextInt input int[] v = new int[n]; v new int[n] n for (int i = 0; i < n; i++) v[i] = input.nextInt(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i v[i] = input.nextInt(); v[i] = input.nextInt() v[i] v i input.nextInt() input.nextInt input Arrays.sort(v) Arrays.sort Arrays v double u = v[0]; u v[0] v 0 for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            u = (u + v[i]) / 2;
        } {
            u = (u + v[i]) / 2;
        } u = (u + v[i]) / 2 u (u + v[i]) / 2 (u + v[i]) u v[i] v i 2 System.out.println(BigDecimal.valueOf(u).toPlainString()) System.out.println System.out System System.out BigDecimal.valueOf(u).toPlainString() BigDecimal.valueOf(u).toPlainString BigDecimal.valueOf(u) BigDecimal.valueOf BigDecimal u String[] args args public class Main {
    public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    }
} public class Main {
    public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    }
} Main
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        java.util.Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int[] v = new int[n];
        for (int i = 0; i < n; i++) v[i] = input.nextInt();
        Arrays.sort(v);
        double u = v[0];
        for (int i = 1; i < n; i++) {
            u = (u + v[i]) / 2;
        }
        System.out.println(BigDecimal.valueOf(u).toPlainString());
    }
}
