next, is y combinator it, or will the be a second act for pauline jessica -- paul and jessica? ?> we are doing so many exciting things. i'm going back to writing. that is what i was doing before y combinator. yhow do you guys want combinator to be remembered? exist.nted to still i wanted to be an institution that persists for a long time. structurally it is more like a university. >> i wanted to change a lot of people's lives. and hopefully, make the world a little bit better place. and jessica livingston, thank you very much. ♪ he's out there. there's a guy out there whose making a name for himself in a sport where your name and maybe a number are what define you. somewhere in that pack is a driver that can intimidate the intimidator. a guy that can take the king 7 and make it 8. heck. maybe even 9. make no mistake about it. they're out there. i guarantee it. welcome to the nascar xfinity series. ? >> by now, you know his story. the kid who started the social network in his harvard dorm room. he became one of the wealthiest men in the world. what mark zuckerberg may not be chang