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

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		int gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	}

} 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 gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	}

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

		Scanner scan = new Scanner(System.in);

		int gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	} main {

		Scanner scan = new Scanner(System.in);

		int gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int gu = scan.nextInt(); gu scan.nextInt() scan.nextInt scan int[] kati = new int[gu]; kati new int[gu] gu for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		} int i=0; int i=0; i 0 i<gu i gu i++ i++ i {
			kati[i] = scan.nextInt();
		} {
			kati[i] = scan.nextInt();
		} kati[i] = scan.nextInt() kati[i] kati i scan.nextInt() scan.nextInt scan Arrays.sort(kati) Arrays.sort Arrays kati double max = kati[0]; max kati[0] kati 0 for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		} int i=1; int i=1; i 1 i<gu i gu i++ i++ i {
			max = (max+kati[i])/2;

		} {
			max = (max+kati[i])/2;

		} max = (max+kati[i])/2 max (max+kati[i])/2 (max+kati[i]) max kati[i] kati i 2 System.out.println(max) System.out.println System.out System System.out max scan.close() scan.close scan String[] args args public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		int gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	}

} public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		int gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	}

} 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 gu = scan.nextInt();
		int[] kati = new int[gu];

		for(int i=0;i<gu;i++) {
			kati[i] = scan.nextInt();
		}

		Arrays.sort(kati);
		double max = kati[0];
		for(int i=1;i<gu;i++) {
			max = (max+kati[i])/2;

		}
		System.out.println(max);

		scan.close();
	}

}
