编辑代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int n = 0;
        int sum = 0;
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextInt()) {
            n=sc.nextInt();
            sum = n*(n+1)/2;
            System.out.println(sum);
            System.out.println();
            sum = 0;
        }
        sc.close();
    }
}