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

public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	}
		

} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	}
		

} Main public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	} main {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	} try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		} {
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		} Scanner scan = new Scanner(System.in) Scanner scan = new Scanner(System.in) new Scanner(System.in) int N = scan.nextInt(); N scan.nextInt() scan.nextInt scan int[] v = new int[N]; v new int[N] N for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			} int i =0; int i =0; i 0 i<N i N i++ i++ i {
				v[i] = scan.nextInt();
			} {
				v[i] = scan.nextInt();
			} v[i] = scan.nextInt() v[i] v i scan.nextInt() scan.nextInt scan Arrays.sort(v) Arrays.sort Arrays v double saigo=v[0]; saigo v[0] v 0 for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			} int i = 1; int i = 1; i 1 i<=N-1 i N-1 N 1 i++ i++ i {
				saigo =(saigo+v[i])/2; 
			} {
				saigo =(saigo+v[i])/2; 
			} saigo =(saigo+v[i])/2 saigo (saigo+v[i])/2 (saigo+v[i]) saigo v[i] v i 2 System.out.println(saigo) System.out.println System.out System System.out saigo String[]args args public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	}
		

} public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	}
		

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

public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			int N = scan.nextInt();
			int[] v = new int[N];
			
			for(int i =0;i<N;i++) {
				v[i] = scan.nextInt();
			}
			
			Arrays.sort(v);
			
			double saigo=v[0];
			
			for(int i = 1;i<=N-1;i++) {
				saigo =(saigo+v[i])/2; 
			}
			
			
			System.out.println(saigo);
			
			
			
			
			
			
			
			
		}
		
		
	}
		

}
