import java.io.*;

public class summation
{
  public static int getInput() throws IOException
  {
    BufferedReader input = new BufferedReader(new
      InputStreamReader(System.in));
    System.out.print("Enter the number n: ");
    return Integer.parseInt(input.readLine());
  }

  public static void addCommas(char[] original)
  {
    int skip=original.length%3;
    if ((skip==0)||(original.length<=3)) skip = 3;
    for (int i=0; i < original.length; i++)
    {
      if ((skip==0)&&(i!=original.length))
      {
        skip=3;
        System.out.print(",");
      }
      System.out.print(original[i]);
      skip--;
    }
  }

  public static void main(String [] arg) throws IOException
  {
    int n = getInput();
    if (n < 1)
    {
      System.out.println("Must be in the set of counting numbers ( >0 )");
      System.exit(0);
    }
    Integer sum = new Integer(n * (n+1) / 2);
    System.out.print("The sum from 1 to "+n+" is ");
    addCommas(sum.toString().toCharArray());
    System.out.println();
  }
}