remopving errors incore java programming

sir error in program:-file does not contain class runnable program:-

class MyRunnable implements Runnable{
    public void run(){
        System.out.println("Run");
    }
    public static void main(String[] args){
        System.out.println("Main");
        MyRunnable mr = new MyRunnable();
        Thread th = new Thread(mr);
        th.start();
    }
}

print("code sample");