Task
📝 **Task:** Predict the output of a reference-sharing program.
```python
a = [1, 2, 3]
b = a
b.append(4)
print(a)
```
📋 Type the list you expect into the output box.
💡 **Hint:** `b = a` does NOT copy the list — both variables point to the SAME list in memory. Changes through `b` are visible through `a`.
🎯 Think: what does `a` look like after `b.append(4)`?