View Code of Problem 30

import java.util.Scanner;

public class Main {

	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);
		int a = scanner.nextInt();
		int b = 0;
		for (int i = 0; i < a+1; i++) {
			b += i;
		}
		System.out.println(b);
		
		
	}

}