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.
import java.util.*;
import java.io.*;
import java.math.*;
import java.util.regex.Matcher;
//linkedhashmap contains the entry in the same order which we are giving and not in sorted way like in hashmaps
public class CF {
    FastScanner in;
    PrintWriter out;
    final static int M=1000001;
    public ArrayList<Integer> input(int m){
        ArrayList<Integer> li= new ArrayList<>();
        for(int i=0;i<m;i++)
            li.add(in.nextInt());
        return li;
    }
    class Pair{
        int x;
        int y;
    }
    public class pair<T,V> {
        private T x;
        private V y;

        public void setY(V y) {
            this.y = y;
        }

        public V getY() {
            return y;
        }

        public void setX(T x) {
            this.x = x;
        }

        public T getX() {
            return x;
        }
    }
    Set<Long> primeFactors(long n)
    {
        // Print the number of 2s that divide n
        Set<Long> li=new HashSet<>();

        while (n%2 == 0)
        {
            li.add(2L);
            n = n/2;
        }

        // n must be odd at this point.  So we can skip one element (Note i = i +2)
        for (long i = 3; i <= Math.sqrt(n); i = i+2)
        {
            // While i divides n, print i and divide n
            while (n%i == 0)
            {
                li.add(i);
                n = n/i;
            }
        }

        // This condition is to handle the case whien n is a prime number
        // greater than 2
        if (n > 2)
            li.add(n);
        return li;
    }
    int res[];
    void sieve(){
        res=new int[10000009];

        int p[]=new int[10000009];
        for(int i=2;i<=10000000;i++){
            if(p[i]==0){
                for(int j=i+i;j<=10000000;j+=i){
                    if(p[i]==0){
                        p[j]=i;
                    }
                    res[i]=res[i-1]+i;
                }
            }
            else{
                res[i]=res[i-1]+p[i];
            }
        }
    }
    public static HashSet<String> getAllPermutations(String str) {

        HashSet<String> permutations = new HashSet<String>();

        if(str == null || str.length() == 0) {
            permutations.add("" );
            return permutations;
        }

        char first = str.charAt(0);
        String remainingString = str.substring(1);
        HashSet<String> words = getAllPermutations(remainingString);
        for(String word: words) {
            for(int i = 0; i <= word.length(); i++) {
                String prefix = word.substring(0, i);
                String suffix = word.substring(i);
                permutations.add(prefix + first + suffix);
            }
        }
        return permutations;
    }

    //    static class Pair<T> {
//        T a;
//        T b;
//
//        public Pair(T a, T b) {
//            this.a = a;
//            this.b = b;
//        }
//    }
    private ArrayList<Integer> adj[];
    private boolean visited[];
    // private boolean visited1[];
    private LinkedList<Integer> q;
    private int level[];
    private int f=0;
    void initialize(){
        visited=new boolean[20001];
        //visited1=new boolean[10001];
        level =new int[20001];
        Arrays.fill(visited,false);
    }
    long mod(long a, long b, long c){		//(a^b)%c
        long ans=1;
        while(b!=0){
            if(b%2==1)
                ans=(ans*a)%c;
            a=(a*a)%c;
            b/=2;
        }
        return ans;
    }

    long modInverse(long a, long p){
        return mod(a,p-2,p);
    }
    void solve() {
     int n=in.nextInt();
        int a[]=new int[n];
        double s=0.0,b=0.0;
        for(int i=0;i<n;i++){
            a[i]=in.nextInt();
            s=s+a[i]/100.0;
        }

        b=(s/(1.0*n));
        BigDecimal ans=BigDecimal.valueOf(s).divide(BigDecimal.valueOf(n),13,BigDecimal.ROUND_CEILING);
        System.out.println(ans.multiply(BigDecimal.valueOf(100.0)));
    }
    private int[] calculateZ(char input[]) {
        int Z[] = new int[input.length];
        int left = 0;
        int right = 0;

        for(int k = 1; k < input.length; k++) {
            if(k > right) {
                left = right = k;
                while(right < input.length && input[right] == input[right - left]) {
                    right++;
                }
                Z[k] = right - left;
                right--;
            } else {
//we are operating inside box
                int k1 = k - left;
//if value does not stretches till right bound then just copy it.
                if(Z[k1] <= right - k + 1) {
                    Z[k] = Z[k1];
                } else { //otherwise try to see if there are more matches.
                    left = k;
                    while(right < input.length && input[right] == input[right - left]) {
                        right++;
                    }
                    Z[k] = right - left;
                    right--;
                }
            }
        }
        return Z;
    }

    void bfs1(int i){
        q=new LinkedList<>();
        q.add(i);
        visited[i]=true;
        while(!q.isEmpty()){
            int s=q.peekFirst();
            q.removeFirst();
            for(int j=0;j<adj[s].size();j++){
                if(!visited[adj[s].get(j)]){
                    level[adj[s].get(j)]=(level[s]+1);
                    q.add(adj[s].get(j));
                    visited[adj[s].get(j)]=true;
                }

            }
        }
    }
    int bfs(int i){
        q=new LinkedList<>();
        q.add(i);
        visited[i]=true;int g=0;
        while(!q.isEmpty()){
            int s=q.peekFirst();
            if(q.size()==1 && adj[s].size()==1)
            {
                g=s;
            }
            q.removeFirst();
            for(int j=0;j<adj[s].size();j++){
                if(!visited[adj[s].get(j)]){
                    //level[adj[s].get(j)]=level[s]+1;
                    q.add(adj[s].get(j));
                    visited[adj[s].get(j)]=true;
                }
            }
        }
        return g;
    }
    boolean dfs(int i,int parent){
        visited[i]=true;
        for(int j=0;j<adj[i].size();j++){
            if(adj[i].get(j)==parent && visited[i])
                continue;
            if(!visited[adj[i].get(j)]) {
                f++;
            }
            if(dfs(adj[i].get(j),i)){
                return true;
            }
        }
        return false;
    }
    static boolean isPali(StringBuilder s){
        for(int i = 0; i < (s.length() >> 1); i++)
            if(s.charAt(i) != s.charAt(s.length() - 1 - i))
                return false;
        return true;
    }
    void run(){
        try {
            in = new FastScanner(new File("B.in"));
            out = new PrintWriter(new File("B.out"));
            solve();
            out.close();
        }
        catch(FileNotFoundException e){
            e.printStackTrace();
        }
    }

    void runIO(){
        in = new FastScanner(System.in);
        out = new PrintWriter(System.out);

        solve();
        out.close();
    }
    class FastScanner{
        BufferedReader br;
        StringTokenizer st;
        public FastScanner(File f){
            try{
                br = new BufferedReader(new FileReader(f));
            }
            catch(FileNotFoundException e){
                e.printStackTrace();
            }
        }
        public FastScanner(InputStream f){
            br = new BufferedReader(new InputStreamReader(f));
        }
        String next(){
            while(st==null || !st.hasMoreTokens()){
                String s = null;
                try{
                    s= br.readLine();
                }
                catch(IOException e){
                    e.printStackTrace();
                }
                if(s==null)
                    return null;
                st = new StringTokenizer(s);
            }
            return st.nextToken();
        }

        boolean hasMoreTokens(){
            while(st==null || !st.hasMoreTokens()){
                String s = null;
                try{
                    s= br.readLine();
                }
                catch(IOException e){
                    e.printStackTrace();
                }
                if(s==null)
                    return false;
                st = new StringTokenizer(s);
            }
            return true;
        }
        int nextInt(){
            return Integer.parseInt(next());
        }
        long nextLong(){
            return Long.parseLong(next());
        }
        double nextDouble(){
            return Double.parseDouble(next());
        }
    }

    public static void main(String[] args) {
        new CF().runIO();
    }
}