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.
// package com.mohitvirmani;

import java.io.*;
import java.util.*;

public class Main {

    //        MAIN FUNCTION
    static FastScanner scanner = new FastScanner(System.in);

    public static void main(String[] args) throws IOException {

//        int testCases = scanner.nextInt();
//        while (testCases-- > 0) {
        solve();
//        }
    }


    //        MAIN CODE
    private static void solve() throws IOException {
        int i = scanner.nextInt();
        int[] arr = new int[i];
        for (int j = 0; j < arr.length; j++) {
            arr[j] = scanner.nextInt();
        }
        double orange = 0;
        double total = 0;
        for (int j = 0; j < arr.length; j++) {
            double x = (double) arr[j] / 100;
            orange = orange + x;
            total++;
        }
//        System.out.println(orange);
//        System.out.println(total);
        System.out.println((orange / total) * 100);
    }


    //    TEMPLATE
    private static boolean prime(int n) {
        int i, m = 0, flag = 0;
        m = n / 2;
        if (n == 0 || n == 1) {
            return false;
        } else {
            for (i = 2; i <= m; i++) {
                if (n % i == 0) {
                    flag = 1;
                    return false;
                }
            }
            return true;
        }
    }

    private static boolean isValid(String s) {
        Stack<Character> stack = new Stack<>();
        for (char c : s.toCharArray()) {
            if (c == '(' || c == '[' || c == '{')
                stack.push(c);
            else {
                if (stack.isEmpty())
                    return false;
                if (c == ')') {
                    if ('(' != stack.pop())
                        return false;
                } else if (c == ']') {
                    if ('[' != stack.pop())
                        return false;
                } else if (c == '}') {
                    if ('{' != stack.pop())
                        return false;
                }
            }
        }
        return stack.isEmpty();
    }

    static int nCr(int n, int r) {
        return fact(n) / (fact(r) *
                fact(n - r));
    }

    static int fact(int n) {
        int res = 1;
        for (int i = 2; i <= n; i++)
            res = res * i;
        return res;
    }

    static int removeDuplicates(int arr[], int n) {
        if (n == 0 || n == 1)
            return n;

        // To store index of next unique element
        int j = 0;

        // Doing same as done in Method 1
        // Just maintaining another updated index i.e. j
        for (int i = 0; i < n - 1; i++)
            if (arr[i] != arr[i + 1])
                arr[j++] = arr[i];

        arr[j++] = arr[n - 1];

        return j;
    }

    private static boolean odd(long n) {
        return n % 2 == 1;
    }

    private static boolean checkIfValueIsPresentInArray(int[] arr, int toCheckValue) {
        Arrays.sort(arr);

        int res = Arrays.binarySearch(arr, toCheckValue);
        if (res > 0) {
            return true;
        }
        return false;
    }

    private static int binarySearch(int target, int start, int end, int[] arr) {
        while (start <= end) {
            int mid = start + (end - start) / 2;
            if (arr[mid] == target) {
                return mid;
            } else if (arr[mid] < target) {
                start = mid + 1;
            } else {
                end = mid - 1;
            }
        }
        return -1;
    }

    static int countDigit(long n) {
        return (int) Math.floor(Math.log10(n) + 1);
    }

    private static int firstDigitOfNumber(int n) {
        // Remove last digit from number
        // till only one digit is left
        while (n >= 10)
            n /= 10;

        // return the first digit
        return n;
    }

    private static int distinctDigitsCount(int n) {
        Set<Integer> set = new HashSet<>();
        while (n >= 10) {
            set.add(n % 10);
            n /= 10;
        }
        set.add(n);
        return set.size();

    }

    static class FastScanner {
        StringTokenizer st;
        BufferedReader br;

        public FastScanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public FastScanner(FileReader r) {
            br = new BufferedReader(r);
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public long[] nextlongArray(int n) throws IOException {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }

        public Long[] nextLongArray(int n) throws IOException {
            Long[] a = new Long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }

        public int[] nextIntArray(int n) throws IOException {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public Integer[] nextIntegerArray(int n) throws IOException {
            Integer[] a = new Integer[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public boolean ready() throws IOException {
            return br.ready();
        }

    }
}