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

public class Main {
	private static double max = 0.0;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	}
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	private static double max = 0.0;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	}
} Main private static double max = 0.0; max 0.0 public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	} main {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	} try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		} {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		} Scanner scanner = new Scanner(System.in) Scanner scanner = new Scanner(System.in) new Scanner(System.in) int N = scanner.nextInt(); N scanner.nextInt() scanner.nextInt scanner double[] array = new double[N]; array new double[N] N for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
				array[i] = scanner.nextDouble();
			} {
				array[i] = scanner.nextDouble();
			} array[i] = scanner.nextDouble() array[i] array i scanner.nextDouble() scanner.nextDouble scanner Arrays.sort(array) Arrays.sort Arrays array double result = array[0]; result array[0] array 0 for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
				result = (result + array[i]) / 2;
			} {
				result = (result + array[i]) / 2;
			} result = (result + array[i]) / 2 result (result + array[i]) / 2 (result + array[i]) result array[i] array i 2 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
	private static double max = 0.0;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	}
} public class Main {
	private static double max = 0.0;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	}
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	private static double max = 0.0;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int N = scanner.nextInt();

			double[] array = new double[N];
			for (int i = 0; i < N; i++) {
				array[i] = scanner.nextDouble();
			}
			Arrays.sort(array);

			double result = array[0];
			for (int i = 0; i < N; i++) {
				result = (result + array[i]) / 2;
			}
			System.out.println(result);
		}
	}
}
