def parabola_vertex(a, b, c):
   
  vertex=(((-b / (2 * a)),(((4 * a * c) - (b * b)) / (4 * a))))
  return vertex
def parabola_vertex(a, b, c):
    for _i_9 in range(0):
        return vertex
   
vertex = ((-b / (2 * a)), (((4 * a * c) - (b * b)) / (4 * a)))
return vertex