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 = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	}
} 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 = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	} main {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = Integer.parseInt(sc.next()); N Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc double[] V = new double[N]; V new double[N] N for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
			V[i] = Double.parseDouble(sc.next());
		} {
			V[i] = Double.parseDouble(sc.next());
		} V[i] = Double.parseDouble(sc.next()) V[i] V i Double.parseDouble(sc.next()) Double.parseDouble Double sc.next() sc.next sc sc.close() sc.close sc Arrays.sort(V) Arrays.sort Arrays V for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		} int i = 0; int i = 0; i 0 i < N-1 i N-1 N 1 i++ i++ i {
			V[i+1] = (V[i] + V[i+1]) / 2;
		} {
			V[i+1] = (V[i] + V[i+1]) / 2;
		} V[i+1] = (V[i] + V[i+1]) / 2 V[i+1] V i+1 i 1 (V[i] + V[i+1]) / 2 (V[i] + V[i+1]) V[i] V i V[i+1] V i+1 i 1 2 System.out.println(V[N-1]) System.out.println System.out System System.out V[N-1] V N-1 N 1 String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	}
} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	}
} 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 = Integer.parseInt(sc.next());
		double[] V = new double[N];
		for(int i = 0;i < N;i++){
			V[i] = Double.parseDouble(sc.next());
		}
		sc.close();
		Arrays.sort(V);
		for(int i = 0;i < N-1;i++){
			V[i+1] = (V[i] + V[i+1]) / 2;
		}
		System.out.println(V[N-1]);
	}
}