
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc PriorityQueue<Double> v = new PriorityQueue<>(); v new PriorityQueue<>() for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        } int i=0; int i=0; i 0 i<n i n i++ i++ i {
            v.add(sc.nextDouble());
        } {
            v.add(sc.nextDouble());
        } v.add(sc.nextDouble()) v.add v sc.nextDouble() sc.nextDouble sc while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        } v.size()>1 v.size() v.size v 1 {
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        } Double a = v.poll(); a v.poll() v.poll v Double b = v.poll(); b v.poll() v.poll v Double c = (a+b)/2.0; c (a+b)/2.0 (a+b) a b 2.0 v.add(c) v.add v c System.out.println(v.poll()) System.out.println System.out System System.out v.poll() v.poll v String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    }
} Main

import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        PriorityQueue<Double> v = new PriorityQueue<>();
        for(int i=0;i<n;i++){
            v.add(sc.nextDouble());
        }
        while(v.size()>1){
            Double a = v.poll();
            Double b = v.poll();
            Double c = (a+b)/2.0;
            v.add(c);
        }
        System.out.println(v.poll());
    }
}