Write a function `get_median(arr1, arr2, n)` that takes two sorted lists `arr1` and `arr2` of the same size `n` and returns the median of the combined sorted list.
The median is the middle value in an ordered list of numbers. If the list has an even number of elements, the median is the average of the two middle numbers.
#### Example Usage
```python [main.nopy]
arr1 = [1, 12, 15, 26, 38]
arr2 = [2, 13, 17, 30, 45]
n = 5
print(get_median(arr1, arr2, n)) # Output: 16.0
arr1 = [2, 4, 8, 9]
arr2 = [7, 13, 19, 28]
n = 4
print(get_median(arr1, arr2, n)) # Output: 8.5
```
#### Constraints
- Both `arr1` and `arr2` are sorted in ascending order.
- Both lists have the same number of elements `n`.
- The function should run efficiently for large values of `n`.