says first we should it's actually three stages right here and they have a diagram so I don't need to draw they have a three stage approach three stages the one on the left is unsupervised pre training so they say let's forget about the labels right now even like your unlabeled data so even the data where we have the labels let's forget about the labels and let's just do unsupervised pre-training now unsupervised pre training in this kind of setting is also known as self supervised pre training and this first stage is done using a