Question: Patrick MacLeamy is the chairman and former CEO of which American architecture, engineering and planning firm?

Context paragraphs:
Allianz De Architecture: Allianz De Architecture is an architecture, design and planning firm that was founded in 2001 in Mumbai, India.  It currently operates offices in Mumbai and Bangalore in India and provides urban design and architectural consulting and planning services.  The firm's designs can be seen at various parts of Mumbai and nearby metropolitan regions and it is known for its work inspired by sustainable modern architectural practices as well as a sensitivity for society and the built-natural environment.

Patrick MacLeamy: Patrick MacLeamy, FAIA, LEED AP, (born October 2, 1942, in Alton, Illinois) is an American architect who is chairman and former CEO of HOK, a global architecture, engineering and planning firm.

Leo A Daly: LEO A DALY, established by Leo A. Daly, Sr. in 1915, is an American architecture, planning, engineering, interior design and program management firm.  The firm’s portfolio includes projects in 91 countries, all 50 U.S. states and the District of Columbia.  The firm currently employs approximately 800 architects, planners, engineers and interior designers in 30 offices.  It consistently ranks as one of the largest architecture, engineering and interior design firms in the United States, and is listed in BD World Architecture’s top firms.

Cambridge Seven Associates: Cambridge Seven Associates, Inc. (C7A) is an American architecture firm founded in 1962 and based in Cambridge, Massachusetts.  The original seven partners, Lou Bakanowsky, Ivan Chermayeff, Peter Chermayeff, Alden Christie, Paul Dietrich, Tom Geismar, and Terry Rankine applied their diverse skills in architecture, planning, exhibit design, graphics, industrial design, and filmmaking to create a single design studio founded on the conviction that each assignment, at any scale, would be an opportunity to apply fresh thinking in search of creative solutions.  The firm was founded upon the idea that the collaborative efforts of a varied group of designers and architects would be far more effective than those of any one individual.  In writing about the firm, the architecture critic Robert Campbell stated, "From the start, the Seven set out to combine architecture with the other design arts - with exhibits, with graphics, and signage, with public art, with product design, with film, even with city planning.  Most of their work is a collaboration among many disciplines..." The practice won the American Institute of Architects Architecture Firm Award in 1993, and was described by the AIA Committee on Design as "an influential and stimulating example, demonstrating new directions of professional practice."

Larry Speck: Lawrence (Larry) Speck is the principal of Austin-based architecture and engineering firm, Page, a professor at the University of Texas at Austin, and holds the W. L. Moody Centennial Professorship in Architecture.  He is a past president of the Texas Society of Architecture.  He was dean of the School of Architecture at the University of Texas at Austin from 1992-2001 and served as Founding Director of the Center of American Architecture and Design from 1982-1990.  He attended the Massachusetts Institute of Technology as an undergraduate receiving two degrees, one in Art and Design from the School of Architecture and one in Management from the Sloan School of Management.  He also received his Master of Architecture from M.I.T.

TVA Architects: TVA Architects, stylized as tva architects, is an American architecture and planning firm based in Portland, Oregon, and founded in 1984 by Robert Thompson, FAIA.  Current principals are Robert Thompson, FAIA, Marc Labadie, CSI, Tim Wybenga, Pamela Saftler, AIA, IIDA, and Mandy Butler, AIA, LEED AP BD+C.  The firm's projects include corporate campus buildings, recreational and training facilities, medical facilities, museums and cultural buildings, in addition to higher education and residential projects.

McKissack &amp; McKissack: McKissack & McKissack is an American architecture and engineering firm based for many years in Nashville, Tennessee, and now based in New York City and Washington, D.C. Founded in 1905, it was the first African-American-owned architectural firm in the United States and is the oldest African American-owned architecture and engineering firm in the country.

HOK (firm): HOK, formerly Hellmuth, Obata + Kassabaum, is an American worldwide design, architecture, engineering and urban planning firm.

Shilpa Architects: Shilpa Architects is an international architecture, design and planning firm that was founded in 1979 in Chennai, India by Sheila Sri Prakash.  The firm was established as a proprietary firm and is the first architecture firm that was founded independently by a woman and has been continuously operated in India.  It currently operates offices in Chennai, Bangalore and Mumbai, in India and in New York City and Chicago in the United States and provides urban design and master planning services.  The firm's designs can be seen at Cholamandal Artists' Village, Mahindra World City, New Chennai, Paranur on GST Road and it is known for its work inspired by sustainable vernacular architectural practices as well as a sensitivity for society and the built-natural environment.

American Architecture Awards: The American Architecture Awards are national and international awards program for new architecture, landscape architecture, interiors, and urban planning in the United States.  The program was launched by the Chicago Athenaeum Museum of Architecture and Design in 1994 to honor and celebrate the most outstanding architecture designed and built or unbuilt throughout the nation or abroad in foreign countries.  The Awards Program is open to all American architecture offices and international firms with projects inside the United States from the past two years.

Supporting paragraphs: Patrick MacLeamy HOK (firm)
Answer: HOK