import java.util.Arrays;
import java.util.Scanner;
public class Main {
@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
}
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
}
} Main @SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
} main {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) float ans=0; ans 0 int N=sc.nextInt(); N sc.nextInt() sc.nextInt sc int v[]=new int[N]; v new int[N] N for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	} int i=0; int i=0; i 0 i<v.length i v.length v v.length i++ i++ i {
		v[i]=sc.nextInt();
	} {
		v[i]=sc.nextInt();
	} v[i]=sc.nextInt() v[i] v i sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v ans=v[0] ans v[0] v 0 for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	} int i=1; int i=1; i 1 i<N i N i++ i++ i {
		ans=(ans+v[i])/2;
	} {
		ans=(ans+v[i])/2;
	} ans=(ans+v[i])/2 ans (ans+v[i])/2 (ans+v[i]) ans v[i] v i 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
}
} public class Main {
@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
}
} Main
import java.util.Arrays;
import java.util.Scanner;
public class Main {
@SuppressWarnings("resource")
public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	float ans=0;
	int N=sc.nextInt();
	int v[]=new int[N];
	for(int i=0;i<v.length;i++) {
		v[i]=sc.nextInt();
	}
	Arrays.sort(v);
	ans=v[0];
	for(int i=1;i<N;i++) {
		ans=(ans+v[i])/2;
	}
	System.out.println(ans);
}
}
