[백준/JAVA] 8393번 합

import java.io.*;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        int n = Integer.parseInt(br.readLine());
        int sum = 0;
        for (int i = 1; i <= n; i++) {
            sum += i;
        }
        StringBuilder sb = new StringBuilder();
        sb.append(sum);
        System.out.print(sb);
    }
}