Which method `sayHellow` we call?

HelloWorld.java

package com.luxoft.oop;

public class HelloWorld {

    public static void main(String[] args) {
        MessagePrinter printer = new MessagePrinter();
        Message msg = new Message("I am message");
        Greetings grt = new Greetings("I am greetings");
        Message msgAsGrt = new Greetings("I am greetings");


        System.out.println(printer.sayHallo(msg));
        System.out.println(printer.sayHallo(grt));

        System.out.println(printer.sayHallo(msgAsGrt));
        System.out.println(printer.sayHallo((Greetings)msgAsGrt));
    }
}

class MessagePrinter {

    public String sayHallo(Message msg) {
        return msg.getText();
    }

    public String sayHallo(Greetings msg) {
        return msg.getText();
    }
}

class Message {
    private String text;

    public Message(String text) {
        this.text = text;
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }
}

class Greetings extends Message {
    public Greetings(String text) {
        super("Hello! I have message for you: " + text);
    }
}