The equation of the planes parallel to the plane \( x - 2y + 2z - 3 = 0 \) which are at unit distance from the point \( (1, 2, 3) \) is \( ax + by + cz + d = 0 \). If \( (b - d) = K(c - a) \), then the positive value of \( K \) is ______________ .
