josh frazier developed online training programs for teachers. kristin winkler has a blog focusing on education and teblg nolg. kristen, you're up first. your question for sal. go for it. >> sal, so with the obvious for the s.t.e.m. subjects, there's increasing group of educators who want to add the a standing for the arts to that and call it s.t.e.a.m. sometime back you brought in the founders of s.m.a.r.t. history into khan academy. do you think expanding into other subject matters anytime soon and maybe second half my question, do you think you would have been equally as successful, say, if you would have started off creating french lessons and creative videos? >> yeah. so as you mentioned about two and a half years we brought in beth harris and stephen zuker, these amazing art historians to make art history videos. the whole point there was to make sure that we are looking at the whole human being, not just the right or left brain. obviously, the core focus of khan academy continues to be primarily mathematics and math-related fields in the s