as part of its greenfest, in 2018 the detroit public zoo gave 1,000 lucky visitors smelly buckets of doubt toothpaste, highly doubt hair gel, so got to be fertilizer. final answer, fertilizer. >> that's what it's used for. >> oh, two! >> exactly right. [applause] $1,000. >> okay. >> see, you're settling in now. >> yeah.0. entrepreneur kristina roth has created supershe island, a private retreat off the coast of finland where, as you can guess from the name, no what are allowed? >> well, i'm thinking supershe island, it's gotta be d, men. final answer. >> would you have bought that? would you have invested in that? >> i don't know. >> [laughs] that's right. >> i like all-inclusive things. yeah. [applause] >> $2,000. our next stop is 3,000. here it is. poking fun at his more famous brother, what musician recorded the 1965 song "i didn't walk the line"? >> oh, my. >> i think that was johnny cash's, "walk the line," right?