import java.util.*;


public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	}
} 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[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] numArray = new int[n]; numArray new int[n] n for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			numArray[i] = sc.nextInt();
        } {
			numArray[i] = sc.nextInt();
        } numArray[i] = sc.nextInt() numArray[i] numArray i sc.nextInt() sc.nextInt sc Arrays.sort(numArray) Arrays.sort Arrays numArray double value = (numArray[0] + numArray[1]) / 2.0; value (numArray[0] + numArray[1]) / 2.0 (numArray[0] + numArray[1]) numArray[0] numArray 0 numArray[1] numArray 1 2.0 for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        } int i = 2; int i = 2; i 2 i < n i n i++ i++ i {
            value = (value + numArray[i]) / 2.0;
        } {
            value = (value + numArray[i]) / 2.0;
        } value = (value + numArray[i]) / 2.0 value (value + numArray[i]) / 2.0 (value + numArray[i]) value numArray[i] numArray i 2.0 System.out.println(value) System.out.println System.out System System.out value String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	}
} Main
import java.util.*;


public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();

		int[] numArray = new int[n];

		for(int i = 0; i < n; i++){
			numArray[i] = sc.nextInt();
        }

        Arrays.sort(numArray);
        double value = (numArray[0] + numArray[1]) / 2.0;
        for(int i = 2; i < n; i++){
            value = (value + numArray[i]) / 2.0;
        }

        System.out.println(value);

	}
}