Question: Who was a member of the IO theater and the host of a CBS talk program? 

full_context: Document 1: Upright Citizens Brigade Theatre: The Upright Citizens Brigade Theatre (shorter UCB Theatre) is an American improvisational theatre and training center, founded by the Upright Citizens Brigade troupe members, including Matt Besser, Amy Poehler, Ian Roberts and Matt Walsh. It has locations in the New York neighborhoods of Chelsea and the East Village as well as the Los Angeles neighborhoods of Hollywood and Sunset Boulevard.
Document 2: Colbert Super PAC: Americans for a Better Tomorrow, Tomorrow (better known as the Colbert Super PAC) was a United States political action committee (PAC) established by Stephen Colbert, who portrayed Dr. Stephen T. Colbert, a mock-conservative political pundit on Comedy Central's satirical television series "The Colbert Report". As a super PAC the organization could raise unlimited sums of money from corporations, unions and other groups, as well as wealthy individuals. Speaking in character, Colbert said the money would be raised not only for political ads, but also "normal administrative expenses, including but not limited to, luxury hotel stays, private jet travel, and PAC mementos from Saks Fifth Avenue and Neiman Marcus."
Document 3: The Late Show with Stephen Colbert: The Late Show with Stephen Colbert is an American late-night talk show hosted by Stephen Colbert, which premiered on September 8, 2015. Produced by Spartina Productions and CBS Television Studios, "The Late Show" "with Stephen Colbert" is the second iteration of CBS's "Late Show" franchise. Stay Human, led by bandleader Jon Batiste, serves as the program's house band, and the announcer is program writer Jen Spyra.
Document 4: Stephen Colbert: Stephen Tyrone Colbert ( , ; born May 13, 1964) is an American comedian, television host, actor, and writer. He is best known for hosting the satirical Comedy Central program "The Colbert Report" from 2005 to 2014, and hosting the CBS talk program "The Late Show with Stephen Colbert" beginning in September 2015.
Document 5: Amy Poehler: Amy Poehler ( ; born September 16, 1971) is an American actress, comedian, director, producer, and writer. After studying improv at Chicago's Second City and ImprovOlympic in the early 1990s, she went to New York City in 1996 to become part of the improvisational comedy troupe Upright Citizens Brigade. The group's act became a half-hour sketch comedy series on Comedy Central in 1998. Along with other members of the comedy group, Poehler was a founder of the Upright Citizens Brigade Theatre.
Document 6: Stephen Colbert (character): Dr. Stephen T. Colbert D.F.A. is the fictionalized persona of political satirist Stephen Colbert, as portrayed on the Comedy Central series "The Colbert Report" and occasionally on "The Late Show with Stephen Colbert" on CBS. Described as a "well-intentioned, poorly informed high-status idiot" and a "self-important right-wing commentator", the character incorporates aspects of the real Colbert's life and interests but is primarily a parody of cable news pundits, particularly former Fox News commentator Bill O'Reilly.
Document 7: The Colbert Report: The Colbert Report ( ) is an American late-night talk and news satire television program hosted by Stephen Colbert that aired four days a week on Comedy Central from October 17, 2005 to December 18, 2014 for 1,447 episodes. The show focused on a fictional anchorman character named Stephen Colbert, played by his real-life namesake. The character, described by Colbert as a "well-intentioned, poorly informed, high-status idiot", is a caricature of televised political pundits. Furthermore, the show satirized conservative personality-driven political talk programs, particularly Fox News's "The O'Reilly Factor". "The Colbert Report" is a spin-off of Comedy Central's "The Daily Show", where he acted as a correspondent for the program for several years while developing the character.
Document 8: Cultural impact of The Colbert Report: "The Colbert Report", which premiered in American cable television on October 17, 2005, has had a massive cultural impact since its inception, when the show introduced the word "truthiness". Issues in and references to American and world culture are attributed to the character played by Stephen Colbert, who calls his followers the Colbert Nation. "The Colbert Report" is a late-night talk and news satire television program hosted by Stephen Colbert that aired on Comedy Central from October 17, 2005 to December 18, 2014 for 1,447 episodes. The show focused on a fictional anchorman character named Stephen Colbert, played by his real-life namesake. The character, described by Colbert as a "well-intentioned, poorly informed, high-status idiot", is a caricature of televised political pundits. Furthermore, the show satirized conservative personality-driven political talk programs, particularly Fox News' "The O'Reilly Factor". "The Colbert Report" is a spin-off of Comedy Central's "The Daily Show", where he acted as a correspondent for the program for several years while developing the character.
Document 9: Harold (improvisation): Harold is a structure used in longform improvisational theatre. Developed by Del Close and brought to fruit through Close's collaboration with Charna Halpern, the Harold has become the signature form of Chicago's iO Theater and the Upright Citizens Brigade Theatre in New York City and Los Angeles. It is now performed by improv troupes and teams across the world.
Document 10: The House Theatre of Chicago: The House Theatre of Chicago is a non-profit, ensemble theatre company in Chicago, IL. The House was founded in 2001 by a group of friends from the British American Drama Academy and Southern Methodist University with the mission of exploring the ideas of Community and Storytelling in order to create a unique theatrical experience for audience members. Since becoming eligible in 2004, The House has been nominated for more than 40 Joseph Jefferson Awards. In 2007, The House became the first recipient of Broadway in Chicago's Emerging Theater Award. Performances currently take place at the Chopin Theatre in Wicker Park.
Document 11: IO Theater: iO, or iO Chicago, (formerly known as "ImprovOlympic") is an improv theater and training center in central Chicago, with a branch in Los Angeles called iO West. The theater both teaches and hosts performances of improvisational comedy. It was founded in 1981 by the late Del Close and Charna Halpern. The theater has many notable alumni, including Amy Poehler and Stephen Colbert.
Document 12: The Comedy &amp; Magic Club: The Comedy & Magic Club is located in Hermosa Beach, California. The club's beachside location has long made it a favorite destination for comedians and audience members alike. Many of the top comics in the industry have and continue to call this their home club. Gabriel Iglesias, Ian Bagg, Cristela Alonzo, Daniel Tosh, Arsenio Hall, and Jay Leno, are all performers who continue to appear regularly. Jay Leno holds a weekly residency on most Sunday evenings and has done so for many years. The audiences are held in high regard by the comedians who frequent the venue as being some of the best in the country. It is a common practice for comedians preparing for a five minute late night appearance to drop by and put the finishing touches on their performances at the club. In addition to their roster of top-tier comedic talent the club boasts an impressive array of magic and variety performers such as Derek Hughes, Rob Zabrecky, The Passing Zone, Danny Cole, Jon Armstrong, Lindsay Benner, and others. The interior of the club also serves as a museum housing comedy memorabilia from Charlie Chaplin, Lucille Ball, Robin Williams, Jerry Seinfeld, Ray Romano, and more on display. The club is open Tuesday through Sunday and also prides itself on being a fundraising force in the local community.
Document 13: The Second City: The Second City is an improvisational comedy enterprise, best known as the first ever on-going improvisational theater troupe based in Chicago. It also has programs that run out of Toronto and Los Angeles. The Second City Theatre opened on December 16, 1959, and has since become one of the most influential and prolific comedy theatres in the world.
Document 14: Jon Stewart: Jon Stewart (born Jonathan Stuart Leibowitz, November 28, 1962) is an American comedian, writer, producer, television host, and occasional actor. He is best known for being the host of "The Daily Show", a satirical news program on Comedy Central, from 1999 to 2015.
Document 15: Late Show (CBS TV series): The Late Show is an American late-night television talk and variety show on CBS. It first aired in August 1993 with host David Letterman, who previously hosted "Late Night with David Letterman" on NBC from 1982 to 1993. Letterman's iteration of the program ran until his retirement on May 20, 2015. Comedian Stephen Colbert, best known for his roles on Comedy Central programs "The Daily Show" and "The Colbert Report", assumed hosting duties in September. The show originates from the Ed Sullivan Theater in the Theater District of Manhattan, New York, and airs live to tape in most U.S. markets at 11:35 p.m. Eastern and Pacific, 10:35 in the Central and Mountain time zones.
ground_truth: Stephen Colbert