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

public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	}

	private static void log(double str) {
		System.out.println(str);
	}

}
 import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	}

	private static void log(double str) {
		System.out.println(str);
	}

} Main public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	} main {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	} @SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int N = scanner.nextInt(); N scanner.nextInt() scanner.nextInt scanner int[] scannerArray = new int[N]; scannerArray new int[N] N for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		} int index = 0; int index = 0; index 0 index < N index N index++ index++ index {
			scannerArray[index] = scanner.nextInt();
		} {
			scannerArray[index] = scanner.nextInt();
		} scannerArray[index] = scanner.nextInt() scannerArray[index] scannerArray index scanner.nextInt() scanner.nextInt scanner Arrays.sort(scannerArray) Arrays.sort Arrays scannerArray double ans = scannerArray[0]; ans scannerArray[0] scannerArray 0 for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		} int index =1; int index =1; index 1 index < N index N index++ index++ index {
			ans = (ans + scannerArray[index]) / 2;
		} {
			ans = (ans + scannerArray[index]) / 2;
		} ans = (ans + scannerArray[index]) / 2 ans (ans + scannerArray[index]) / 2 (ans + scannerArray[index]) ans scannerArray[index] scannerArray index 2 log(ans) log ans String[] args args private static void log(double str) {
		System.out.println(str);
	} log {
		System.out.println(str);
	} System.out.println(str) System.out.println System.out System System.out str double str str public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	}

	private static void log(double str) {
		System.out.println(str);
	}

} public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	}

	private static void log(double str) {
		System.out.println(str);
	}

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

public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner scanner = new Scanner(System.in);

		int N = scanner.nextInt();

		int[] scannerArray = new int[N];

		for (int index = 0; index < N; index++) {
			scannerArray[index] = scanner.nextInt();
		}

		Arrays.sort(scannerArray);

		double ans = scannerArray[0];

		for(int index =1; index < N; index++) {
			ans = (ans + scannerArray[index]) / 2;
		}
		log(ans);
	}

	private static void log(double str) {
		System.out.println(str);
	}

}

