mr. chen: if i could try to address your question. i think one point is that we know from the evidence that methadone works very well. we've been using it for decades. we also know that the other does work in a similar way in terms of the outcomes measured against in terms of criminal activity, in terms of health. your point about street use of it is a good one. i think there are two issues to that. i spent a morning in a clinic prescribing it to people. i happen to have my -- as a pinch hitter. i asked every one of them how they started. i asked every one of them what things they went through. and a lot of them actually started with the street drug. this is really self-medication as much as anything. some of them said, yeah, i got high a little bit in the beginning. but after that, it was just about not withdrawing. and so if you have demand that's not meeting supply, then they're going to buy it on the street. i think there are ways to be more mindful about how you regulate the prescriptions. we have to be very careful we're not jus