import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    }
} import java.util.PriorityQueue; PriorityQueue java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    }
} Main public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    } main {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    } Scanner std = new Scanner(System.in); std new Scanner(System.in) int n = std.nextInt(); n std.nextInt() std.nextInt std PriorityQueue<Integer> pq = new PriorityQueue<>(); pq new PriorityQueue<>() for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            pq.add(std.nextInt());
        } {
            pq.add(std.nextInt());
        } pq.add(std.nextInt()) pq.add pq std.nextInt() std.nextInt std Integer first = pq.poll(); first pq.poll() pq.poll pq double ans = first; ans first while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        } !pq.isEmpty() pq.isEmpty() pq.isEmpty pq {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        } Integer value = pq.poll(); value pq.poll() pq.poll pq ans += value ans value ans /= 2.0 ans 2.0 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    }
} Main
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner std = new Scanner(System.in);
        int n = std.nextInt();
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            pq.add(std.nextInt());
        }

        Integer first = pq.poll();
        double ans = first;
        while (!pq.isEmpty()) {
            Integer value = pq.poll();
            ans += value;
            ans /= 2.0;
        }

        System.out.println(ans);
    }
}
