Package problem

CODE

// file name: AccessPackage.java

import package_name.MyPackage;

public class AccessPackage {
    public static void main(String[] args) {
        MyPackage obj = new MyPackage();
        obj.display();
    }
}

// file name: my_package/MyPackage.java
package package_name;

public class MyPackage {
    public void display() {
        System.out.println("Hello World");
    }
}