import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    }

} import java.io.BufferedInputStream; BufferedInputStream java.io import java.io.BufferedOutputStream; BufferedOutputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    }

} Main public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    } main {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    } try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        } {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        } BufferedInputStream in = new BufferedInputStream(System.in) BufferedInputStream in = new BufferedInputStream(System.in) new BufferedInputStream(System.in) PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out)) PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out)) new PrintWriter(new BufferedOutputStream(System.out)) Scanner sc = new Scanner(in); sc new Scanner(in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc double[] vs = new double[n]; vs new double[n] n for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt(); int i = 0; int i = 0; i 0 i < vs.length i vs.length vs vs.length i++ i++ i vs[i] = sc.nextInt(); vs[i] = sc.nextInt() vs[i] vs i sc.nextInt() sc.nextInt sc Arrays.sort(vs) Arrays.sort Arrays vs for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0; int i = 1; int i = 1; i 1 i < n i n i++ i++ i vs[i] = (vs[i - 1] + vs[i]) / 2.0; vs[i] = (vs[i - 1] + vs[i]) / 2.0 vs[i] vs i (vs[i - 1] + vs[i]) / 2.0 (vs[i - 1] + vs[i]) vs[i - 1] vs i - 1 i 1 vs[i] vs i 2.0 out.println(vs[n - 1]) out.println out vs[n - 1] vs n - 1 n 1 String[] args args public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    }

} public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    }

} Main
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedInputStream in = new BufferedInputStream(System.in);
             PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out))) {

            Scanner sc = new Scanner(in);

            // 11:46-

            // 11:54-

            int n = sc.nextInt();
            double[] vs = new double[n];
            for (int i = 0; i < vs.length; i++) vs[i] = sc.nextInt();

            Arrays.sort(vs);

            for (int i = 1; i < n; i++) vs[i] = (vs[i - 1] + vs[i]) / 2.0;

            out.println(vs[n - 1]);
        }
    }

}
