In the fourth blog, we did the code testing. We tried to run the code with different images of writing as the input. It also to understand the workflow. We also try to find another referenced in the youtube. It is talking about how to use Keras and TensorFlow codes at the same time and the library uses mnist for the number zero until nine in large twenty-eight times twenty-eighth. Finally, we decide to use from github to our reference is https://github.com/githubharald/SimpleHTR