import java.util.*;

public class Main {
	public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	}
} import java.util.*; util.* java public class Main {
	public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	}
} Main public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] arr = new int[n]; arr new int[n] n for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			arr[i] = sc.nextInt();
		} {
			arr[i] = sc.nextInt();
		} arr[i] = sc.nextInt() arr[i] arr i sc.nextInt() sc.nextInt sc Arrays.sort(arr) Arrays.sort Arrays arr double result = arr[0]; result arr[0] arr 0 for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		} int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
			result = (result + arr[i]) / 2.0;
		} {
			result = (result + arr[i]) / 2.0;
		} result = (result + arr[i]) / 2.0 result (result + arr[i]) / 2.0 (result + arr[i]) result arr[i] arr i 2.0 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
	public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	}
} public class Main {
	public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	}
} Main
import java.util.*;

public class Main {
	public static void main (String[] args)  {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
			arr[i] = sc.nextInt();
		}
		Arrays.sort(arr);
		double result = arr[0];
		for (int i = 1; i < n; i++) {
			result = (result + arr[i]) / 2.0;
		}
		System.out.println(result);
	}
}
