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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	}

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

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	}

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

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	} main {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc double[] relese = new double[N]; relese new double[N] N for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		} int i = 0; int i = 0; i 0 i<N i N i++ i++ i {
			relese[i] = sc.nextDouble();
		} {
			relese[i] = sc.nextDouble();
		} relese[i] = sc.nextDouble() relese[i] relese i sc.nextDouble() sc.nextDouble sc Arrays.sort(relese) Arrays.sort Arrays relese double anser = relese[0]; anser relese[0] relese 0 for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			} int i = 1 ; int i = 1 ; i 1 i<N i N i++ i++ i {
				anser = (anser+relese[i])/2;
			} {
				anser = (anser+relese[i])/2;
			} anser = (anser+relese[i])/2 anser (anser+relese[i])/2 (anser+relese[i]) anser relese[i] relese i 2 System.out.println(anser) System.out.println System.out System System.out anser String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	}

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	}

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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		double[] relese = new double[N];
		for(int i = 0; i<N; i++) {
			relese[i] = sc.nextDouble();
		}
		Arrays.sort(relese);
			double anser = relese[0];
			for(int i = 1 ; i<N;i++) {
				anser = (anser+relese[i])/2;
			}
			System.out.println(anser);

	}

}
