sentence with the piece missing and we have the missing piece so they generate this label data set from unlabeled data so it works in these kinds of situations so in speech recognition well in sentence like if you're trying to understand the semantics of sentences you can take a sentence remove one piece and see if the system can learn to fill in the blanks and similarly with images we can take out a small part of the image and see kind of a system learn to spot fill in that missing part of the image and actually it has been