How to defined the N and P in adjusted R-squared for evaluating a BPNNs

Hi,everyone.

I am using a back-propagationg neural networks(BPNNs) to fit a economic nonlinear cuvre. The structure of the BPNNs is 7 nodes in input layer, 10 nodes in hidden layer and 1 node in output layer. Moreover, the dataset holds 36 samples. After training, I want to use the adjusted R-squared to evaluating the performance on the regressed curve of BPNNs. How can I define the n and p in the adjusted R-squared forumla in here? And, is it right to use the adjusted R-squared to evaluating the NNs? Thank you!!