[백준/Java] 2557번 : Hello World!

public class Main{
    public static void main(String[] args){
        System.out.println("Hello World!");
    }
}

OR

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        bw.write("Hello World!");
        bw.flush();
        bw.close();
    }
}