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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	}
} 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	}
} 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	} 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	} 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 sc.close() sc.close sc Arrays.sort(v) Arrays.sort Arrays v double p = v[0]; p v[0] v 0 for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
			p = (p + v[i]) / 2;
		} {
			p = (p + v[i]) / 2;
		} p = (p + v[i]) / 2 p (p + v[i]) / 2 (p + v[i]) p v[i] v i 2 System.out.println(p) System.out.println System.out System System.out p 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	}
} 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	}
} 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();
		}
		sc.close();
		Arrays.sort(v);
		double p = v[0];
		for(int i = 0; i < N; i++) {
			p = (p + v[i]) / 2;
		}
		System.out.println(p);
	}
}
