+267 Lana defines a function f(x) which is given by the formula f(x) = x^2, but only on a domain she has specified which consists of finitely many values x; she leaves the function undefined for all other x. Given that the range of f(x) is {0,1,2,3,4,5,6,7,8,9\}, what is the maximum number of points that could be in its domain?
