using System;

public class Program

{

    public static void Main()

    {

    //De Leon Gauna Jose Miguel

    //3A TPR

        int n,x, suma;

        suma=0;

        Console.WriteLine("Dame N numeros a sumar:");

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

        for (x=1;x<=n;x++){

            suma=suma+x;

        }

        Console.WriteLine("Suma: " +suma);

    }

}