An integer \(N\) (1 ≤ \(N\) ≤ 9999), representing a four-digit number. If \(N < 1000\), the upper digits are filled with 0s. The number of datasets does not exceed 10,000. Input ends when \(N\) is 0000.

### Example Input:

```
6174
2012
3333
0000
```

### Function Signature:
Write a function f(inputs) that takes in the input.
```python
def f(inputs: List[int]):
    '''
    inputs: a list of integers
    '''
```