I have to find complete sufficient statistic of the following pdf
$$f(x|\theta)=\frac{\theta}{(1+x)^{(1+\theta)}},\quad 0<x<\infty,\theta>0.$$
My Attempt:
The joint density
$$f(\mathbf x|\theta)=\prod_{i=1}^{n}\frac{\theta}{(1+x_i)^{(1+\theta)}}$$
$$=\theta^n\prod_{i=1}^{n}\exp[-(1+\theta)\log(1+x_i)]$$ $$=\theta^n\exp[-(1+\theta)\sum_{i=1}^{n}\log(1+x_i)]$$
So, $\sum_{i=1}^{n}\log(1+x_i)$ is complete sufficient.
But it seems to me I am wrong. What will be the correct answer ?