import java.util.*;

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

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