```python
def driest_window(rain: list[int], width:    if not isinstance(rain, list) or not all(isinstance(x, int) and x >= 0 for x in rain):
        raise ValueError("Invalid rain data")
    if not isinstance(width, int) or width < raise ValueError("Invalid width value")
    if width <= 0 or width > len(rain):
        raise ValueError("Invalid window size")

    min =    min[rain[i:i + width]       min_min =    min(rainers,       min_index = rainers.index(list_min)
    return min_min
```