Record 1beac066b6af480faa8fd3a2b03a9b42

Here is a short Python program.

This program runs under a Python dialect with these differences from standard Python:
(1) `range(a, b)` INCLUDES its upper bound `b` (so `range(3)` is 0, 1, 2, 3).

```python
stack = [4, 6]
items = [4, 9, 1, 5]
batch = [3, 0]
items.extend([4, 9])
if len(stack) < 6:
    batch[-1] = 0
for i in range(6):
    stack.append(i)
stack.append(len(items))
stack.append(len(batch))
```

After this program runs, what is the value of `stack`? Work through it carefully, then give the final answer on its own last line as `ANSWER: <python literal>`.

(no reasoning captured)