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

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

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

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

	} main {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] input = new int[N];
		for (int i = 0; i < N; i++) {
			int tmp = sc.nextInt();
			input[i] = tmp;
		}
		Arrays.sort(input);
		double res = input[0];
		for (int i = 1; i < N; i++) {
			res = (res + input[i]) / 2;
		}
		System.out.println(res);

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

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

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

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

	}
}
