Question: Who is in charge of the city where Isaac Nicola was born?

full_context: Document 1: Leon Ichaso: Leon Ichaso was born in Havana August 3, 1948, into a family of well-known writers, journalists and artists. His father, Justo Rodríguez Santos, was one of Cuba's most respected poets and a pioneer in broadcast TV and radio -and his mother Antonia Ichaso had a radio magazine show in the 1940s.
Document 2: Niño Rivera: Niño Rivera was born Andrés Perfecto Eleuterio Goldino Confesor Echevarría Callava on April 18, 1919 in Pinar del Río, Cuba. He started playing the bongo in his uncle's band, Sexteto Caridad, when he was only 5 years old. In 1924 his family moved to Havana, where he took up the tres in Sexteto Boloña, alternating with Sexteto Cárdenas. In 1929 he went back to Pinar del Río, where he reorganized the Sexteto Caridad, before returning to Havana in 1934. He learned to master the tres as a student of the classical guitarist Guyún (Vicente González Rubiera) and the arranger Félix Guerrero. In 1935 he replaced Eliseo Silveira in Tata Gutiérrez's Sexteto Bolero, which he would later direct. He often played in Radio Mil Diez. In 1942 he established the Septeto Rey de Reyes, a son septet featuring a harmonic vocal quartet which he directed. At this time, Rivera became part of the nascent filin movement and started working as a composer/arranger.
Document 3: Havana: The current mayor of Havana ("President of the People's Power Provincial Assembly") is Marta Hernández Romero, she was elected on March 5, 2011.
Document 4: Carmen Cardinali Paoa: Chilean deputy Interior Minister Rodrigo Ubilla appointed Carmen Cardinali as Governor of Easter Island in early September 2010 to replace Edmunds. Cardinali's challenges included archeological preservation of the island's heritage and revamping the tourist industry. She served as a Governor until March 2014, being replaced by Marta Raquel Hotus Tuki, appointed by president Michelle Bachelet.
Document 5: Miami: In recent years the city government, under Mayor Manny Diaz, has taken an ambitious stance in support of bicycling in Miami for both recreation and commuting. Every month, the city hosts "Bike Miami", where major streets in Downtown and Brickell are closed to automobiles, but left open for pedestrians and bicyclists. The event began in November 2008, and has doubled in popularity from 1,500 participants to about 3,000 in the October 2009 Bike Miami. This is the longest-running such event in the US. In October 2009, the city also approved an extensive 20-year plan for bike routes and paths around the city. The city has begun construction of bike routes as of late 2009, and ordinances requiring bike parking in all future construction in the city became mandatory as of October 2009.
Document 6: Mexico City: The first elected head of government was Cuauhtémoc Cárdenas. Cárdenas resigned in 1999 to run in the 2000 presidential elections and designated Rosario Robles to succeed him, who became the first woman (elected or otherwise) to govern Mexico City. In 2000 Andrés Manuel López Obrador was elected, and resigned in 2005 to run in the 2006 presidential elections, Alejandro Encinas being designated by the Legislative Assembly to finish the term. In 2006, Marcelo Ebrard was elected for the 2006–2012 period.
Document 7: Marie Atkins: Marie Atkins was mayor of the Kingston and Saint Andrew Corporation (KSAC) from 1989 to 2003. Atkins was the third female mayor for Kingston & St. Andrew, Jamaica, and is the longest-serving mayor to date for Kingston & St. Andrew. She is the first Jamaican to become the president of the World Conference of Mayors.
Document 8: Isaac Nicola: Isaac Nicola Romero (11 April 1916 in Havana, Cuba – 14 July 1997) was a prominent Cuban guitarist and one of the founders of the modern Cuban Guitar School. He was also brother of Clara (Cuqui) Nicola.
Document 9: Eliseo Grenet: Eliseo Grenet Sánchez (12 June 1893 in Havana – 4 December 1950) was a Cuban pianist and a leading composer/arranger of the day. He composed music for stage shows and films, and some famous Cuban dance music. Eliseo was one of three musical brothers, all composers, the others being Emilio ("'Neno'," 1901–1941) and Ernesto (1908–1981). Emilio went on composing even after having a leg bitten off by a shark in 1930; Ernesto was a drummer who became leader of the Tropicana's orchestra.
Document 10: Nicola Samale: Nicola Samale (born 14 September 1941 in Castelnuovo d'Istria, Italy, now Podgrad, Ilirska Bistrica in Slovenia), is a composer and conductor.
Document 11: Joaquín Clerch: Joaquín Clerch (born 1965 in Havana, Cuba) is a classical guitarist and composer. He was a close friend and protégé of Cuban guitarist and composer Leo Brouwer. Clerch's composition "Yemaya" won first prize in both the 1987 National Cuban Composition Competition and the 1987 Toronto International Guitar Competition. He currently resides in Düsseldorf, Germany where he is a Professor of Guitar at the Robert-Schumann-Hochschule Düsseldorf (Robert Schumann University Düsseldorf).
Document 12: Cerro, Havana: Cerro is one of the 15 municipalities or boroughs ("municipios" in Spanish) in the city of Havana, Cuba. As of 2016 it is considered "one of Havana’s poorest municipalities."
Document 13: Jorge Isaac: Jorge Isaac (born 1974 in Caracas, Venezuela) completed his professional training under with Walter van Hauwe at the Conservatorium van Amsterdam in 2000. In 2002 Isaac received his Master's degree in contemporary performance and live electronics at the same institution. In 2006 he was appointed as Professor of recorder at the Conservatorium van Amsterdam, carrying on the famous Amsterdam Recorder School.
Document 14: Houston: The city of Houston has a strong mayoral form of municipal government. Houston is a home rule city and all municipal elections in the state of Texas are nonpartisan. The City's elected officials are the mayor, city controller and 16 members of the Houston City Council. The current mayor of Houston is Sylvester Turner, a Democrat elected on a nonpartisan ballot. Houston's mayor serves as the city's chief administrator, executive officer, and official representative, and is responsible for the general management of the city and for seeing that all laws and ordinances are enforced.
Document 15: Moisés Simons: Moisés Simons (born Moisés Simón Rodríguez; 24 August 1889 in Havana, Cuba – 28 June 1945 in Madrid, Spain), was a leading Cuban composer, pianist, and orchestra leader. He was the composer of "El Manisero" ("The Peanut Vendor" in English) which is considered by many to be the most famous piece of music created by a Cuban musician and has since been recorded by other musicians from around the world hundreds of times.
ground_truth: Marta Hernández Romero
sub_queries: What was Isaac Nicola's city of birth? Answer: Havana
Who was in charge of Havana ? Answer: Marta Hernández Romero