import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    }
} import java.util.Arrays; Arrays 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 = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    } main {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = Integer.parseInt(sc.next()); N Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int[] v = new int[N]; v new int[N] N for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            v[i] = Integer.parseInt(sc.next());
        } {
            v[i] = Integer.parseInt(sc.next());
        } v[i] = Integer.parseInt(sc.next()) v[i] v i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc Arrays.sort(v) Arrays.sort Arrays v float tmp = (v[0] + v[1]) / 2f; tmp (v[0] + v[1]) / 2f (v[0] + v[1]) v[0] v 0 v[1] v 1 2f for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        } int i = 2; int i = 2; i 2 i < N i N i++ i++ i {
            tmp = (tmp + v[i]) / 2f;
        } {
            tmp = (tmp + v[i]) / 2f;
        } tmp = (tmp + v[i]) / 2f tmp (tmp + v[i]) / 2f (tmp + v[i]) tmp v[i] v i 2f System.out.println(tmp) System.out.println System.out System System.out tmp String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];
        for (int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        Arrays.sort(v);
        float tmp = (v[0] + v[1]) / 2f;
        for (int i = 2; i < N; i++) {
            tmp = (tmp + v[i]) / 2f;
        }

        System.out.println(tmp);
    }
}