The answer: `1` and `2`.

The first handler triggers, because it's not removed by `removeEventListener`. To remove the handler we need to pass exactly the function that was assigned. And in the code a new function is passed, that looks the same, but is still another function.

To remove a function object, we need to store a reference to it, like this:

```js
function handler() {
  alert(1);
}

button.addEventListener("click", handler);
button.removeEventListener("click", handler);
```

The handler `button.onclick` works independently and in addition to `addEventListener`.