Miami University is one of five schools, along with the United States Naval Academy, the University of Michigan, Stanford University, and the University of Delaware, that have graduated both a U.S. President and a Super Bowl winning quarterback.[117] Benjamin Harrison, the 23rd President of the United States, graduated from Miami in 1852.[118] Charles Anderson, the 27th Governor of Ohio, graduated from Miami in 1833.[119] Chung Un-chan, the previous Prime Minister of South Korea, received his master's degree from Miami in economics in 1972.[120] Other politicians include U.S. Senator Maria Cantwell of Washington, U.S. House of Representatives Speaker Paul Ryan of Wisconsin, and U.S. Representative Susan Brooks of Indiana.[121][122] Rita Dove, a Pulitzer Prize winner and the first African-American United States Poet Laureate, graduated summa cum laude from Miami.[123] Other prominent alumni in business include: Marne Levine, COO of Instagram, C. Michael Armstrong, former chairman & CEO of AT&T, former chairman/CEO of Hughes Aircraft Co. and former chairman of the President's Export Council, and Richard T. Farmer, founder and CEO emeritus of Cintas.