using System;

public class Program

{

    public static void Main()

    {

        int i, sum=0, num;

            Console.Write("Enter a number: ");

            num = Convert.ToInt32(Console.ReadLine());

            for (i = 1; i <= num; i++)

            {

                Console.Write(" {0} + ", i);

                sum = sum + i;

            }

            Console.WriteLine("Sum of N Numbers : " + sum);

    }

}

​

​