import java.util.*;

class Main {
    public static void main(String[] args) throws java.lang.Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        }
        System.out.println(v[n - 1]);
        sc.close();
    }
} import java.util.*; util.* java class Main {
    public static void main(String[] args) throws java.lang.Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        }
        System.out.println(v[n - 1]);
        sc.close();
    }
} Main public static void main(String[] args) throws java.lang.Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        }
        System.out.println(v[n - 1]);
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        }
        System.out.println(v[n - 1]);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc double[] v = new double[n]; v new double[n] n for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            v[i] = sc.nextDouble();
        } {
            v[i] = sc.nextDouble();
        } v[i] = sc.nextDouble() v[i] v i sc.nextDouble() sc.nextDouble sc Arrays.sort(v) Arrays.sort Arrays v for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        } int i = 0; int i = 0; i 0 i < n - 1 i n - 1 n 1 i++ i++ i {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        } {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        } v[i + 1] = (v[i] + v[i + 1]) / 2d v[i + 1] v i + 1 i 1 (v[i] + v[i + 1]) / 2d (v[i] + v[i + 1]) v[i] v i v[i + 1] v i + 1 i 1 2d System.out.println(v[n - 1]) System.out.println System.out System System.out v[n - 1] v n - 1 n 1 sc.close() sc.close sc String[] args args
import java.util.*;

class Main {
    public static void main(String[] args) throws java.lang.Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double[] v = new double[n];
        for (int i = 0; i < n; i++) {
            v[i] = sc.nextDouble();
        }
        Arrays.sort(v);
        for (int i = 0; i < n - 1; i++) {
            v[i + 1] = (v[i] + v[i + 1]) / 2d;
        }
        System.out.println(v[n - 1]);
        sc.close();
    }
}
