An integer T (1 ≤ T ≤ 50), representing the number of datasets.
A list of T strings, each containing up to 80 characters. Each string consists of integers and operation symbols {'+', '-', '*', '/'}, separated by single spaces.

### Example Input:

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

### Function Signature:
Write a function f(T, datasets) that takes in the input. 
def f(T: int, datasets: List[str]): 
    ''' 
    T: an integer 
    datasets: a list of strings
    '''