//
//	Assignment ???  Project ??
//
//	Author: ??
//	Instructor: Dr. John Wang
//
//	Goal: out numbers ...
//

import java.util.Scanner;
class OutNums
{
	public static void main(String[] args)
	{
		Scanner input = new Scanner(System.in);
		// sum up 1 - 10
		int sum = 0;
		int N;	// keyboard

		// prompt
		System.out.print("Input N: ");
		N = input.nextInt();

		for(int i=1; i<=N; i++)
		{
			//System.out.print(i + "  ");
			sum = sum + i;
		}

		System.out.println("sum = " + sum);

		System.out.println("\n\n\nDone.\n\n\n");
	}
}