import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	}

} import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	}

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

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	} main {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	} Scanner       scan         = new Scanner(System.in); scan new Scanner(System.in) List<Integer> inputNumbers = new ArrayList<Integer>(); inputNumbers new ArrayList<Integer>() double        ave          = 0; ave 0 int count = scan.nextInt(); count scan.nextInt() scan.nextInt scan for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	} int i=0; int i=0; i 0 i<count i count i++ i++ i {

    		inputNumbers.add(scan.nextInt());

    	} {

    		inputNumbers.add(scan.nextInt());

    	} inputNumbers.add(scan.nextInt()) inputNumbers.add inputNumbers scan.nextInt() scan.nextInt scan scan.close() scan.close scan Collections.sort(inputNumbers) Collections.sort Collections inputNumbers ave = inputNumbers.get(0) ave inputNumbers.get(0) inputNumbers.get inputNumbers 0 for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	} int i=1; int i=1; i 1 i<inputNumbers.size() i inputNumbers.size() inputNumbers.size inputNumbers i++ i++ i {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	} {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	} ave = (ave + inputNumbers.get(i)) / 2 ave (ave + inputNumbers.get(i)) / 2 (ave + inputNumbers.get(i)) ave inputNumbers.get(i) inputNumbers.get inputNumbers i 2 System.out.println(ave) System.out.println System.out System System.out ave String[] args args public class Main {

	public static void main(String[] args) {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	}

} public class Main {

	public static void main(String[] args) {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	}

} Main
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

    	Scanner       scan         = new Scanner(System.in);
    	List<Integer> inputNumbers = new ArrayList<Integer>();
    	double        ave          = 0;

    	int count = scan.nextInt();

    	for(int i=0; i<count; i++) {

    		inputNumbers.add(scan.nextInt());

    	}

    	scan.close();

    	Collections.sort(inputNumbers);
    	ave = inputNumbers.get(0);

    	for(int i=1; i<inputNumbers.size(); i++) {

    		ave = (ave + inputNumbers.get(i)) / 2;

    	}

    	System.out.println(ave);

	}

}