[백준 Java] 기하: 직사각형과 삼각형 - 15894번: 수학은 체육과목 입니다

 

 

import java.io.*;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long n = Integer.parseInt(br.readLine());

        bw.write(String.valueOf(4 * n));

        br.close();
        bw.flush();
        bw.close();
    }
}