using System;

public class Program

{

    public static void Main(string[] args)

    {

        Console.Write("How many number to input: ");

        int input = int.Parse(Console.ReadLine());

        Console.WriteLine();

        while (input <= 1 )

        {

         Console.Write("Error! input again");

         input = int.Parse(Console.ReadLine()); 

        }   

        int sum = 0;

        for (int i = 1; i <= input; i++)

        {

            Console.Write("Input number {0}: ", i);

            int number = int.Parse(Console.ReadLine());

            sum = sum + number; 

        }

        Console.WriteLine();

        Console.WriteLine("Summation is {0}",sum);

        Console.WriteLine("Average   is {0}",sum / (float)input);

    }

}