import java.util.*;
import java.lang.*;

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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    }
} import java.util.*; util.* java import java.lang.*; lang.* 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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    }
} 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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    } 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 < n; i++) {
            v[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            v[i] = sc.nextInt();
        } {
            v[i] = sc.nextInt();
        } v[i] = sc.nextInt() v[i] v i sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v ArrayList<Double> q = new ArrayList<>(); q new ArrayList<>() for (int i = 0; i < n; i++) {
            q.add(v[i]);
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            q.add(v[i]);
        } {
            q.add(v[i]);
        } q.add(v[i]) q.add q v[i] v i while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        } q.size() > 1 q.size() q.size q 1 {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        } double val = (q.remove(0) + q.remove(0)) / 2; val (q.remove(0) + q.remove(0)) / 2 (q.remove(0) + q.remove(0)) q.remove(0) q.remove q 0 q.remove(0) q.remove q 0 2 q.add(val) q.add q val Collections.sort(q) Collections.sort Collections q System.out.println(q.get(0)) System.out.println System.out System System.out q.get(0) q.get q 0 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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    }
} 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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    }
} Main
import java.util.*;
import java.lang.*;

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 < n; i++) {
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        ArrayList<Double> q = new ArrayList<>();
        
        for (int i = 0; i < n; i++) {
            q.add(v[i]);
        }
        //System.out.println("---");
        while(q.size() > 1) {
            double val = (q.remove(0) + q.remove(0)) / 2;
            //System.out.println(val);
            q.add(val);
            Collections.sort(q);
        }
        System.out.println(q.get(0));
    }
}