# Sort numbers using only 2 hidden layers

I'm reading the cornerstone paper Sequence to Sequence Learning with Neural Networks by Ilya Sutskever and Quoc Le. On the first page, it briefly mentions that:

A surprising example of the power of DNNs is their ability to sort
N N-bit numbers using only 2 hidden layers of quadratic size


Can anyone briefly outline how to sort numbers using only 2 hidden layers?