import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[] values = new int[num];
		for(int i = 0; i < num; i++)values[i] = sc.nextInt();
		Arrays.sort(values);
		double ans = (double)values[0];
		for(int value : values){
			ans = (value + ans) / 2;
		}

		System.out.println(ans);
	}
}

 import java.util.*; util.* java class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[] values = new int[num];
		for(int i = 0; i < num; i++)values[i] = sc.nextInt();
		Arrays.sort(values);
		double ans = (double)values[0];
		for(int value : values){
			ans = (value + ans) / 2;
		}

		System.out.println(ans);
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[] values = new int[num];
		for(int i = 0; i < num; i++)values[i] = sc.nextInt();
		Arrays.sort(values);
		double ans = (double)values[0];
		for(int value : values){
			ans = (value + ans) / 2;
		}

		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[] values = new int[num];
		for(int i = 0; i < num; i++)values[i] = sc.nextInt();
		Arrays.sort(values);
		double ans = (double)values[0];
		for(int value : values){
			ans = (value + ans) / 2;
		}

		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int num = sc.nextInt(); num sc.nextInt() sc.nextInt sc int[] values = new int[num]; values new int[num] num for(int i = 0; i < num; i++)values[i] = sc.nextInt(); int i = 0; int i = 0; i 0 i < num i num i++ i++ i values[i] = sc.nextInt(); values[i] = sc.nextInt() values[i] values i sc.nextInt() sc.nextInt sc Arrays.sort(values) Arrays.sort Arrays values double ans = (double)values[0]; ans (double)values[0] values 0 for(int value : values){
			ans = (value + ans) / 2;
		} int value values {
			ans = (value + ans) / 2;
		} {
			ans = (value + ans) / 2;
		} ans = (value + ans) / 2 ans (value + ans) / 2 (value + ans) value ans 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args
import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int[] values = new int[num];
		for(int i = 0; i < num; i++)values[i] = sc.nextInt();
		Arrays.sort(values);
		double ans = (double)values[0];
		for(int value : values){
			ans = (value + ans) / 2;
		}

		System.out.println(ans);
	}
}


