An integer \(N\) (1 ≤ \(N\) ≤ 50), representing the number of datasets.
A list of strings \(L\) of size \(N\), where each string represents a sequence of integers and operations in Reverse Polish Notation (a string of up to 80 characters consisting 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(N, L) that takes in the input.
def f(N: int, L: List[str]):
    '''
    N: an integer
    L: a list of strings
    '''