An integer D (1 ≤ D ≤ 50), representing the number of datasets.
A list of strings F of size D, where each string is up to 80 characters long and consists of integers and operation symbols separated by a single space.

### Example Input:

```
3
10 2 12 - /
3 4 - 7 2 3 * + *
-1 -2 3 + +
```

### Function Signature:
Write a function f(D, F) that takes in the input.
def f(D: int, F: List[str]):
    ''' 
    D: an integer 
    F: a list of strings
    '''