[SWEA][JAVA] 2025. N줄덧셈

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
 
class Solution {
    
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    
    public static void main(String[] args) throws IOException {
        
        int input = Integer.parseInt(br.readLine());
        int res = 0;
        for(int i=1; i<=input; i++) {
            res+=i;
        }
        System.out.println(res);
        
    }
}