Question: Pentair and Charles Schwab Corporation, are located in which country's initials?
Context: Soundview Technology Group (formerly NASDAQ:SNDV) was an American technology-focused securities and investment banking firm known primarily for its equity research on technology and other growth oriented companies.  The company was acquired by Charles Schwab in 2003. Brian Christopher Tucker (born December 27, 1975) is an American businessman and real estate developer.  Tucker has served as an executive at Charles Schwab Corporation and founded Punta Brava Golf Club, a private golf and surf club with billionaire Red McCombs and Tiger Woods.  Tucker serves as President and Principal in Tactical Air Operations, the contracted Static Line and Freefall School of the United States Navy as well as Skydive San Diego.  Tucker serves on the board of the The Century Club of San Diego, which hosts the Farmers Insurance Open at Torrey Pines Golf Course as well as other charitable endeavors. 101 Montgomery (also known as The Schwab Building) is a high-rise office building located in San Francisco, California.  The building rises 404 feet (123 meters) in the northern region of San Francisco’s Financial District.  It contains 28 floors, and was completed in 1984.  101 Montgomery is currently tied with Embarcadero West as the 39th-tallest building in the city.  The building's developer was Cahill Contractors.  The building has earlier served as the headquarters of Charles Schwab & Company. Pentair plc (PNR) is a multinational diversified industrial company incorporated in Ireland with tax residency in UK, with its main U.S. office located in Minneapolis, Minnesota.  Pentair was founded in the US, where roughly half of the company's revenue is derived as of 2015.  However, PNR was reorganized in 2014, shifting the corporate domicile from Switzerland to Ireland. The Charles Schwab Corporation is a bank and brokerage firm, based in San Francisco, California.  It was founded in 1971 by Charles R. Schwab.  It is on the list of largest banks in the United States and is one of the largest brokerage firms in the United States.  The company provides services for individuals and institutions that are investing online.  The company offers an electronic trading platform for the purchase and sale of financial securities including common stocks, preferred stocks, futures contracts, exchange-traded funds, options, mutual funds, and fixed income investments.  It also provides margin lending, and cash management services.  The company also provides services through registered investment advisers. U.S. Trust, Bank of America Private Wealth Management (formerly known as U.S. Trust Corporation) was founded in 1853 as the United States Trust Company of New York.  It operated independently until 2000, when it was acquired by Charles Schwab, and Co., and subsequently was sold to, and became a subsidiary of, Bank of America in 2007.  U.S. Trust provides investment management, wealth structuring, and credit and lending services to clients. Philip Berber is an Irish-born, Texas-based technology entrepreneur, now engaged in philanthropy, international aid, social entrepreneurship and impact investing.  He sold CyBerCorp, his online brokerage for day traders, to Charles Schwab for $488m in 2000.  He and his wife Donna then formed and funded A Glimmer of Hope, pledging $100 million of Schwab stock to endow the foundation. The Financial District is a neighborhood in San Francisco, California, that serves as its main central business district.  It is home to the city's largest concentration of corporate headquarters, law firms, insurance companies, real estate firms, banks, savings and loans, and other financial institutions.  All six San Francisco Fortune 500 companies—McKesson, Wells Fargo, PG&E, Gap, Charles Schwab, and Salesforce.com—are located in the district. Charles Robert Schwab (born July 29, 1937) is an American investor, financial executive, and philanthropist.  He is the founder and chairman of the Charles Schwab Corporation.  He pioneered discount sales of equity securities starting in 1975.  His company became by far the largest discount securities dealer in the United States.  He retired as CEO in 2008, but remains chairman and is the largest shareholder. optionsXpress is a service of the Charles Schwab Corporation that provides an electronic trading platform for investing online, specializing in the trading of options.
Answer: U.S.