Little Vasya loves orange juice very much. That's why any food and drink in his kitchen necessarily contains orange juice. There are n drinks in his fridge, the volume fraction of orange juice in the i-th drink equals pi percent.

One day Vasya decided to make himself an orange cocktail. He took equal proportions of each of the n drinks and mixed them. Then he wondered, how much orange juice the cocktail has.

Find the volume fraction of orange juice in the final drink.

Input

The first input line contains a single integer n (1 ≤ n ≤ 100) — the number of orange-containing drinks in Vasya's fridge. The second line contains n integers pi (0 ≤ pi ≤ 100) — the volume fraction of orange juice in the i-th drink, in percent. The numbers are separated by a space.

Output

Print the volume fraction in percent of orange juice in Vasya's cocktail. The answer will be considered correct if the absolute or relative error does not exceed 10  - 4.

Examples

Input

3
50 50 100


Output

66.666666666667


Input

4
0 25 50 75


Output

37.500000000000

Note

Note to the first sample: let's assume that Vasya takes x milliliters of each drink from the fridge. Then the volume of pure juice in the cocktail will equal <image> milliliters. The total cocktail's volume equals 3·x milliliters, so the volume fraction of the juice in the cocktail equals <image>, that is, 66.(6) percent.
/**
 * Created by Grand on 27.07.2015.
 */
import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class tr implements Runnable {

    final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;

    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok = new StringTokenizer("");

    public static void main(String[] args) {
        new Thread(null, new tr(), "", 128 * (1L << 20)).start();

    }

    void init() throws FileNotFoundException {
        Locale.setDefault(Locale.US);
        /*if (ONLINE_JUDGE) {
            in = new BufferedReader(new FileReader("island2.in"));
            out = new PrintWriter("island2.out");
        } else {*/
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        //}
    }

    long timeBegin, timeEnd;

    void time() {
        timeEnd = System.currentTimeMillis();
        System.err.println("Time = " + (timeEnd - timeBegin));
    }

    public void run() {
        try {
            timeBegin = System.currentTimeMillis();

            init();
            solve();

            out.close();
            time();
        } catch (Exception e) {
            e.printStackTrace(System.err);
            System.exit(-1);
        }
    }


    String readString() throws IOException {

        while (!tok.hasMoreTokens()) {
            try {
                tok = new StringTokenizer(in.readLine());
            } catch (Exception e) {
                return null;
            }
        }
        return tok.nextToken();
    }

    String readString(String s) throws IOException {
        while (!tok.hasMoreTokens()) {
            try {
                tok = new StringTokenizer(in.readLine(), s + "\n \t");
            } catch (Exception e) {
                return null;
            }
        }
        return tok.nextToken();
    }

    double readDouble() throws IOException {
        return Double.parseDouble(readString());
    }

    int readInt() throws IOException {
        return Integer.parseInt(readString());
    }

    long readLong() throws IOException {
        return Long.parseLong(readString());
    }

    int readInt(String s) throws IOException {
        return Integer.parseInt(readString(s));
    }

    boolean isPrime(int a) throws IOException {
        int del = 0;
        if (a == 2) {
            return false;
        }
        for (int i = 2; i < Math.sqrt(a) + 1; i++) {
            if (a % i == 0) {
                del = i;
                break;
            }
        }
        if (del > 0) {
            return false;
        } else return true;
    }

    public BigInteger bigFactorial(int num) throws IOException {
        BigInteger fact = new BigInteger("1");
        BigInteger i = new BigInteger("1");
        BigInteger one = new BigInteger("1");
        for (int j = 0; j < num; j++) {
            fact = fact.multiply(i);
            i = i.add(one);
//out.println(fact.toString()+" "+i.toString());
        }
//fact = fact.add(one);

        return fact;
    }

    public long factorial(int num) throws IOException {
        long res = 1;
        for (int i = 2; i <= num; i++) {
            res *= i;
        }
        return res;
    }

    //Random rd=new Random(System.currentTimeMillis());
    public int[] readIntArr(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = readInt();
            //a[n-i-1] = - a[i];
        }
        return a;
    }

    class Pair implements Comparable {
        int sumue, start;

        public Pair(int sumue, int start) {

        }

        public int getsumue() {
            return sumue;
        }

        public void setsumue(int sumue) {
            this.sumue = sumue;
        }

        public int getQ() {
            return start;
        }

        public void setQ(int q) {
            this.start = q;
        }

        @Override
        public int compareTo(Object o) {
            if (this.sumue > ((Pair) o).sumue) {
                return 1;
            }
            if (this.sumue < ((Pair) o).sumue) {
                return -1;
            }
            if (this.sumue == ((Pair) o).sumue && this.start > ((Pair) o).start) {
                return 1;
            }
            if (this.sumue == ((Pair) o).sumue && this.start < ((Pair) o).start) {
                return -1;
            }

            return 0;
        }

        @Override
        public String toString() {
            return "Pair{" +
                    "sumue=" + sumue +
                    ", start=" + start +
                    '}';
        }
    }

    Random rnd = new Random();

    class two {
        ArrayList<Integer> zn = new ArrayList<Integer>();
        int sum;
        int sumpr;

        public two(int sum, int sumpr) {
            this.sum = sum;
            this.sumpr = sumpr;
        }

        public ArrayList<Integer> getZn() {
            return zn;
        }

        public void setZn(ArrayList<Integer> zn) {
            this.zn = zn;
        }

        public int getSum() {
            return sum;
        }

        public void setSum(int sum) {
            this.sum = sum;
        }

        public int getSumpr() {
            return sumpr;
        }

        public void setSumpr(int sumpr) {
            this.sumpr = sumpr;
        }
    }


    class four implements Comparable<four> {
        int l, r, price;
        String lic;

        public four(int l, int r, int price, String lic) {
            this.l = l;
            this.r = r;
            this.price = price;
            this.lic = lic;
        }

        public int getL() {
            return l;
        }

        public void setL(int l) {
            this.l = l;
        }

        public int getR() {
            return r;
        }

        public void setR(int r) {
            this.r = r;
        }

        public int getPrice() {
            return price;
        }

        public void setPrice(int price) {
            this.price = price;
        }

        public String getLic() {
            return lic;
        }

        public void setLic(String lic) {
            this.lic = lic;
        }

        @Override
        public int compareTo(four four) {
            return this.r - four.r;
        }
    }


    void solve() throws Exception {
        int n=readInt();
        double curr=0;
        for (int i = 0; i < n; i++) {
            double r = readDouble();
            curr+= (r);
        }
        System.out.println(curr/n);

    }


}
