cat mask and predict you know there and so what master LUN does is it just takes your input sequence and it's it corrupts a few locations 15% in the case of bird and it trains the model to predict what's at those masked locations so you know might in in this case there's no like left requirement to write requirement it just randomly selects 15% and this allows you to have bi-directional like representations you can't leak the word because it's masked in the inputs whereas for a standard left-right right-left Ella you kind of