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

class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		double[] p=new double[N];
		for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		}
		Arrays.sort(p);
		double ans = 0d;
		ans=p[0];
		for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		}
		p(ans);
	}
	public static void p(Object o) {
		System.out.println(o);
	}
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		double[] p=new double[N];
		for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		}
		Arrays.sort(p);
		double ans = 0d;
		ans=p[0];
		for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		}
		p(ans);
	}
	public static void p(Object o) {
		System.out.println(o);
	}
} Main public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		double[] p=new double[N];
		for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		}
		Arrays.sort(p);
		double ans = 0d;
		ans=p[0];
		for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		}
		p(ans);
	} main {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		double[] p=new double[N];
		for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		}
		Arrays.sort(p);
		double ans = 0d;
		ans=p[0];
		for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		}
		p(ans);
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int N=sc.nextInt(); N sc.nextInt() sc.nextInt sc double[] p=new double[N]; p new double[N] N for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		} int i=0; int i=0; i 0 i<N i N i++ i++ i {
			p[i]=sc.nextDouble();
		} {
			p[i]=sc.nextDouble();
		} p[i]=sc.nextDouble() p[i] p i sc.nextDouble() sc.nextDouble sc Arrays.sort(p) Arrays.sort Arrays p double ans = 0d; ans 0d ans=p[0] ans p[0] p 0 for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		} int i=1; int i=1; i 1 i<N i N i++ i++ i {
			ans=(ans+p[i])/2.0;
		} {
			ans=(ans+p[i])/2.0;
		} ans=(ans+p[i])/2.0 ans (ans+p[i])/2.0 (ans+p[i]) ans p[i] p i 2.0 p(ans) p ans String[] args args public static void p(Object o) {
		System.out.println(o);
	} p {
		System.out.println(o);
	} System.out.println(o) System.out.println System.out System System.out o Object o o
import java.util.Arrays;
import java.util.Scanner;

class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		double[] p=new double[N];
		for(int i=0; i<N; i++) {
			p[i]=sc.nextDouble();
		}
		Arrays.sort(p);
		double ans = 0d;
		ans=p[0];
		for(int i=1; i<N; i++) {
			ans=(ans+p[i])/2.0;
		}
		p(ans);
	}
	public static void p(Object o) {
		System.out.println(o);
	}
}