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

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

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    }
}
 import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    }
} Main public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    } main {
        try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    } try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        } {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        } Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] array = new int[n]; array new int[n] n for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                array[i] = sc.nextInt();
            } {
                array[i] = sc.nextInt();
            } array[i] = sc.nextInt() array[i] array i sc.nextInt() sc.nextInt sc Arrays.sort(array) Arrays.sort Arrays array double res = (array[0] + array[1]) / 2.0; res (array[0] + array[1]) / 2.0 (array[0] + array[1]) array[0] array 0 array[1] array 1 2.0 for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            } int i = 2; int i = 2; i 2 i < n i n i++ i++ i {
                res = (res + array[i]) / 2.0;
            } {
                res = (res + array[i]) / 2.0;
            } res = (res + array[i]) / 2.0 res (res + array[i]) / 2.0 (res + array[i]) res array[i] array i 2.0 System.out.println(res) System.out.println System.out System System.out res String[] args args public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    }
} public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in)) {
            int n = sc.nextInt();

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

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

            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = sc.nextInt();
            }
            Arrays.sort(array);

            double res = (array[0] + array[1]) / 2.0;
            for (int i = 2; i < n; i++) {
                res = (res + array[i]) / 2.0;
            }
            System.out.println(res);
        }
    }
}

