import javax.swing.JOptionPane;
public class Oppg2a {
	public static void main(String[] random) {
	String stringput;
	String output = null;
	stringput = JOptionPane.showInputDialog("Skriv inn et helt tall");
	int input = Integer.parseInt(stringput);	
	for(int i=1 ; i <= input ; i++){
		output = output + i;
		}
	System.out.println(output);
	System.exit(0);		
	}
 
}