import java.util.*;

public class Sum // Change the name of class for your purpose
{
	public static void main(String [] args)
	{
		// Input: a positve integer
		// Output: to compute the sum of integers 1, 2, ... N

		int count = 1;
		int sum = 0;
		
		Scanner con;
		con = new Scanner(System.in);
		
		System.out.println("The program computes the sum of 1, 2, ... N");
		System.out.println("Enter the integer N:");
	   int N = con.nextInt();
		
		while( count <= N)
		{
		     // Loop body
		     sum = sum+count; 
			  count++;
		}
		
		System.out.println("The sum of 1, 2, ... " + N + " is " + sum);
	}
}