What does the following Java code output?

import java.util.ArrayList;
import java.util.List;
public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = new ArrayList<>();
        numbers.add(10);
        numbers.add(20);
        numbers.add(30);
        numbers.remove(Integer.valueOf(20));
        System.out.println(numbers.contains(20));
    }
}