simplicity and maybe it was also our downfall. >> yeah. we had more time to test it, i mean, our contraption back there made a few waterfalls in places where we didn't want it. >> everybody can see ways to make your structure better. we never get it right the first time, but we're going to go through things many times quickly, roughly. prototyping is a very effective way to make intellectual progress very quickly and the second thing is it is just really satisfying. this is light hearted. later in the course, i mean, the team in haiti will be dealing with people who are completely disabled with spinal cord damage from the earthquake there. they're going to be dealing with people in africa mall nourished. ultimately we look at serious stuff, and a big chunk of this is about teamwork and about getting to know each other and doing stuff that is not easy.