using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    Console.WriteLine("Nhap do dai mang ");

        int d = Convert.ToInt32(Console.ReadLine());

        int [] a=new int[50];

        //int [] b=new int[50];

        int dem =0;

        Console.WriteLine("Nhap phan tu trong mang ");

        for (int i=0;i<d;i++)

        {

            int m=Convert.ToInt32(Console.ReadLine());  

            a[i]=m;

            dem=dem+m;

        }

        //Console.WriteLine("Nhap phan tu trong mang 2");

        //for (int i=0; i<d; i++)

        //{

            //int n=Convert.ToInt32(Console.ReadLine());

            //b[i]=n;

        //}

        double tb=(double)dem/d;

        Console.Write("Gia tri trung binh cua mang la: "+tb);

    }

}