import java.util.Scanner;

public class SumToN {
  public static void main(String[] args) {
    int sum = 0;
    Scanner sc = new Scanner(System.in);

    System.out.print("Enter a number: ");
    int n = sc.nextInt();

    for (int i=1; i<=n; i=i+1) {
      sum = sum + i;
    }

    System.out.println("The sum from 1 to "+n+" is "+sum);
  }
}

//Copyright 2010-2012 : Evan Golub