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