import java.util.*;
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	}
} import java.util.*; util.* java public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc double a[] = new double[n]; a new double[n] n for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		} int i=0; int i=0; i 0 i<n i n i++ i++ i {
			a[i]=sc.nextInt();
		} {
			a[i]=sc.nextInt();
		} a[i]=sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc Arrays.sort(a) Arrays.sort Arrays a double ans=a[0]; ans a[0] a 0 for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		} int i=1; int i=1; i 1 i<n i n i++ i++ i {
			ans+=a[i];
			ans/=2;
		} {
			ans+=a[i];
			ans/=2;
		} ans+=a[i] ans a[i] a i ans/=2 ans 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	}
} public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	}
} Main
import java.util.*;
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n=sc.nextInt();
		double a[] = new double[n];
		for(int i=0;i<n;i++) {
			a[i]=sc.nextInt();
		}
		Arrays.sort(a);
		double ans=a[0];	
		for(int i=1;i<n;i++){
			ans+=a[i];
			ans/=2;
		}
		System.out.println(ans);
	}
}