import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    }

} import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    }

} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc List<Integer> v = new ArrayList<>(); v new ArrayList<>() for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            v.add(sc.nextInt());
        } {
            v.add(sc.nextInt());
        } v.add(sc.nextInt()) v.add v sc.nextInt() sc.nextInt sc sc.close() sc.close sc Collections.sort(v) Collections.sort Collections v double value = v.remove(0); value v.remove(0) v.remove v 0 for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        } int i = 0; int i = 0; i 0 i < n - 1 i n - 1 n 1 i++ i++ i {
            value = (value + v.remove(0)) / 2.0;
        } {
            value = (value + v.remove(0)) / 2.0;
        } value = (value + v.remove(0)) / 2.0 value (value + v.remove(0)) / 2.0 (value + v.remove(0)) value v.remove(0) v.remove v 0 2.0 System.out.println(value) System.out.println System.out System System.out value String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    }

} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    }

} Main
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> v = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            v.add(sc.nextInt());
        }
        sc.close();
        Collections.sort(v);

        double value = v.remove(0);
        for (int i = 0; i < n - 1; i++) {
            value = (value + v.remove(0)) / 2.0;
        }
        System.out.println(value);
    }

}
