those things is really critical yeah yeah yeah I mentioned I would fly in here but I don't think I'm allowed to yeah that's a good question we identified the dynamics model which is somewhere between them but we definitely model the dynamics of this drone it's not like a model free black box and the reason because it's definitely model vulnerable so it is you know the propellers there are aerodynamic effects that we understand quite well there's the inertia's of the drone and properties of it and so we we model