import java.util.Scanner;

public class Sum_Iterative
{
	public static void main(String[] args)
	{
		Scanner scan = new Scanner(System.in);
		System.out.print("Enter a number: ");
		int n= scan.nextInt();
		
		int sum=0;
		
		for(int i=1; i<=n; i++)
		{
			sum += i;
		}
		
		System.out.println("Sum of the numbers from 1 to " + n + " = " + sum);
	}
}