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

public class Main {

	public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	}

	private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	}

} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	}

	private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	}

} Main public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	} main {

		Main main = new Main();
		main.exec();

	} Main main = new Main(); main new Main() main.exec() main.exec main String[] args args private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	} exec {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	} int n; n Scanner sc = new Scanner(System.in); sc new Scanner(System.in) 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] = (double)sc.nextInt();
		} int i = 0 ; int i = 0 ; i 0 i < n i n i++ i++ i {
			v[i] = (double)sc.nextInt();
		} {
			v[i] = (double)sc.nextInt();
		} v[i] = (double)sc.nextInt() v[i] v i (double)sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v double ans = v[0]; ans v[0] v 0 for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		} int i = 1 ; int i = 1 ; i 1 i < n i n i++ i++ i {
			ans = (ans + v[i]) / 2;
		} {
			ans = (ans + v[i]) / 2;
		} ans = (ans + v[i]) / 2 ans (ans + v[i]) / 2 (ans + v[i]) ans v[i] v i 2 System.out.println(ans) System.out.println System.out System System.out ans sc.close() sc.close sc public class Main {

	public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	}

	private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	}

} public class Main {

	public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	}

	private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	}

} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Main main = new Main();
		main.exec();

	}

	private void exec() {

		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		double[] v = new double[n];
		for(int i = 0 ; i < n ; i++) {
			v[i] = (double)sc.nextInt();
		}
		Arrays.sort(v);
		double ans = v[0];
		for(int i = 1 ; i < n ; i++) {
			ans = (ans + v[i]) / 2;
		}
		System.out.println(ans);
		sc.close();

	}

}
