def parabola_directrix(a, b, c):
   
  directrix=((int)(c - ((b * b) + 1) * 4 * a ))
  return directrix
def is_not_prime(n):
    import math
    
    result = False
    for i in range(2,int(math.sqrt(n)) + 1):
        if n % i == 0:
            result = True
    return result