like how to Train it and so on so let's say we don't always do this sometimes we do this other thing and sometimes we do that and there's several ways of biasing this model but basically you do this mask which modeling and then because they also want to evaluate on let's say entire sequence tasks or tasks that span multiple sentences what they do is the second free training task at the same time as you can see here where they feed two sentences so that's the first sentence that's the second sentence they feed these two sentences as an input so