import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	}

} import java.math.BigDecimal; BigDecimal java.math import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	}

} Main public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	} main {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	} try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		} {
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		} Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc Integer[] v = new Integer[n]; v new Integer[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 BigDecimal mixed = new BigDecimal(v[0].toString()); mixed new BigDecimal(v[0].toString()) for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			} int i = 1 ; int i = 1 ; i 1 i < n i n i++ i++ i {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			} {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			} mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2")) mixed mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2")) mixed.add(new BigDecimal(v[i].toString())).divide mixed.add(new BigDecimal(v[i].toString())) mixed.add mixed new BigDecimal(v[i].toString()) new BigDecimal("2") System.out.println(mixed.toString()) System.out.println System.out System System.out mixed.toString() mixed.toString mixed String[] args args public class Main {

	public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	}

} public class Main {

	public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	}

} Main
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		try(Scanner sc = new Scanner(System.in)){
			int n = sc.nextInt();
			Integer[] v = new Integer[n];
			for(int i = 0 ; i < n ; i++) {
				v[i] = sc.nextInt();
			}
			Arrays.sort(v);
			BigDecimal mixed = new BigDecimal(v[0].toString());
			for(int i = 1 ; i < n ; i++) {
				mixed = mixed.add(new BigDecimal(v[i].toString())).divide(new BigDecimal("2"));
			}
			System.out.println(mixed.toString());
		}

	}

}
