백준 8393 / 자바

www.acmicpc.net/problem/8393

8393번: 합

import java.io.*;

public 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;
		}
		
		System.out.println(sum);
		
		br.close();
		
	}

}