hello please help!!! i keep getting the answer to be 0 and dont know where im going wrong........

Let X1, X2,...., Xn be a random sample from the distribution having pdf

f(x | q)= q x^-2 if x greater than or equal to q.
0 otherwise.
Determine the likelihood function for q on [0, infinity ) and hence derive the maximum likelihood estimator of q.

Giving reasons, state whether or not the maximum likelihood estimator is unbiased.