You will be shown an excerpt from a computer science scientific research paper, followed by a question about the paper. Please answer the question. Do not include any text in your response other than the answer.

Context: ModelSRCNN consists of three layers: patch extraction/representation, non-linear mapping and reconstruction. Filters of spatial sizes 9\times 9, 1\times 1, and 5\times 5 were used respectively.

Question: What are the layers of the Model SRCNN?
SRCNN has three layers in the following order: patch extraction/representation, non-linear mapping, and reconstruction.