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

public class Main {
    static Scanner stdIn = new Scanner(System.in);
    public static void main(String[] args){
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

        System.out.println(sum);
    }
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.Collections; Collections java.util public class Main {
    static Scanner stdIn = new Scanner(System.in);
    public static void main(String[] args){
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

        System.out.println(sum);
    }
} Main static Scanner stdIn = new Scanner(System.in); stdIn new Scanner(System.in) public static void main(String[] args){
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

        System.out.println(sum);
    } main {
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

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

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

        System.out.println(sum);
    }
} public class Main {
    static Scanner stdIn = new Scanner(System.in);
    public static void main(String[] args){
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

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

public class Main {
    static Scanner stdIn = new Scanner(System.in);
    public static void main(String[] args){
        int n = stdIn.nextInt();
        int[] v = new int[n];
        for(int i=0; i<n; i++){
            v[i] = stdIn.nextInt();
        }

        Arrays.sort(v);
        double sum = (double)(v[0] + v[1]) / 2;
        for(int i=2; i<n; i++){
            sum = (double)(sum + v[i]) / 2;
        }

        System.out.println(sum);
    }
}