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

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	}
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	}
} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	} main {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int N = scan.nextInt(); N scan.nextInt() scan.nextInt scan int[] vals = new int[N]; vals new int[N] N for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
			vals[i] = scan.nextInt();
		} {
			vals[i] = scan.nextInt();
		} vals[i] = scan.nextInt() vals[i] vals i scan.nextInt() scan.nextInt scan Arrays.sort(vals) Arrays.sort Arrays vals double ans = vals[0]; ans vals[0] vals 0 for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		} int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
			ans = (ans + vals[i]) / 2;
		} {
			ans = (ans + vals[i]) / 2;
		} ans = (ans + vals[i]) / 2 ans (ans + vals[i]) / 2 (ans + vals[i]) ans vals[i] vals i 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int[] vals = new int[N];
		for (int i = 0; i < N; i++) {
			vals[i] = scan.nextInt();
		}
		Arrays.sort(vals);
		double ans = vals[0];
		for (int i = 1; i < N; i++) {
			ans = (ans + vals[i]) / 2;
		}
		System.out.println(ans);
	}
} Main
import java.util.Arrays;
import java.util.Scanner;

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