백준 8393번(반복문)

 

 

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        int a = in.nextInt();
        in.close();
        int sum = 0;

        for (int i = 1; i <= a; i++) {
            sum += i;
        }
        System.out.println(sum);
    }
}