import java.util.*;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    }
} Main public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    } main {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    } 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[] ary = new int[n]; ary new int[n] n for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            ary[i] = Integer.parseInt(sc.next());
        } {
            ary[i] = Integer.parseInt(sc.next());
        } ary[i] = Integer.parseInt(sc.next()) ary[i] ary i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc Arrays.sort(ary) Arrays.sort Arrays ary double x = ary[0]; x ary[0] ary 0 for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            x = (x + ary[i]) / 2;
        } {
            x = (x + ary[i]) / 2;
        } x = (x + ary[i]) / 2 x (x + ary[i]) / 2 (x + ary[i]) x ary[i] ary i 2 System.out.print(x) System.out.print System.out System System.out x String[] args args public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    }
} public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int[] ary = new int[n];

        for (int i = 0; i < n; i++) {
            ary[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(ary);
        double x = ary[0];
        for (int i = 1; i < n ; i++) {
            x = (x + ary[i]) / 2;
        }
        System.out.print(x);
    }
}