------
## 最终结论
```python
def parabola_directrix(a, b, c):
    # The directrix of a parabola given by the equation y = a(x - h)^2 + k
    # where (h, k) is the vertex and p is the distance from the vertex to the focus or directrix
    # can be calculated as follows:
    
    # For the standard form y = ax^2 + bx + c, we can find the vertex (h, k)
    h = -b / (2 * a)
    k = a * h ** 2 + b * h + c
    
    # The distance p from the vertex to the focus is given by 1/(4a)
    p = 1 / (4 * a)
    
    # The directrix is located at y = k - p
    directrix = k - p
    
    return int(directrix)

# Test cases
assert parabola_directrix(5,3,2) == -198
assert parabola_directrix(9,8,4) == -2336
assert parabola_directrix(2,4,6) == -130
```