import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc List<Double> list = new ArrayList<Double>(); list new ArrayList<Double>() for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        } {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        } int v = sc.nextInt(); v sc.nextInt() sc.nextInt sc list.add(new Double(v+"")) list.add list new Double(v+"") Collections.sort(list) Collections.sort Collections list double result = list.get(0); result list.get(0) list.get list 0 for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        } int i = 1; int i = 1; i 1 i < list.size() i list.size() list.size list i++ i++ i {
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        } {
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        } Double v2 = list.get(i); v2 list.get(i) list.get list i result = (result + v2) / 2.0 result (result + v2) / 2.0 (result + v2) result v2 2.0 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        List<Double> list = new ArrayList<Double>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();
            list.add(new Double(v+""));
        }
        Collections.sort(list);

        double result = list.get(0);
        for(int i = 1; i < list.size() ; i++){
            Double v2 = list.get(i);
            result = (result + v2) / 2.0;
        }
        System.out.println(result);
    }
}
