import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    }
} Main public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    } main {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    } Scanner s = new Scanner(System.in); s new Scanner(System.in) int n = s.nextInt(); n s.nextInt() s.nextInt s List<Double> l = new ArrayList<>(); l new ArrayList<>() for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            l.add(s.nextDouble());
        } {
            l.add(s.nextDouble());
        } l.add(s.nextDouble()) l.add l s.nextDouble() s.nextDouble s Collections.sort(l) Collections.sort Collections l double ch = 0; ch 0 double ans = 0; ans 0 for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        } double i l {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        } {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        } if (ans == 0) {
                ans = i;
            } ans == 0 ans 0 {
                ans = i;
            } ans = i ans i ans=(ans+i)/2 ans (ans+i)/2 (ans+i) ans i 2 System.out.print(ans) System.out.print System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        List<Double> l = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            l.add(s.nextDouble());
        }
        Collections.sort(l);
        double ch = 0;
        double ans = 0;
        for (double i : l) {
            if (ans == 0) {
                ans = i;
            }
            ans=(ans+i)/2;
        }
        System.out.print(ans);
    }
}