The government of the City and County of San Francisco utilizes the "strong mayor" form of mayoral/council government, composed of the Mayor, Board of Supervisors, several elected officers, and numerous other entities. It is the only consolidated city-county in California, and one of only thirteen charter counties of California. The fiscal year 2019–20 city and county budget was approximately $12.3 billion. Organization San Francisco utilizes the "strong mayor" form of mayoral/council government, composed of the mayor, Board of Supervisors, several elected officers, and numerous other entities. San Francisco voters use ranked-choice voting to elect the mayor, supervisors, and other elective officers. Mayor The Mayor of San Francisco is the head of the executive branch of the city and county government. The mayor has the responsibility to enforce all city laws, administer and coordinate city departments and intergovernmental activities, set forth policies and agendas to the Board of Supervisors, and prepare and submit the city budget at the end of each fiscal year. The mayor has the powers to either approve or veto bills passed by the San Francisco Board of Supervisors, participate in meetings of the Board of Supervisors and its committees, appoint a replacement to fill vacancies in all city elected offices until elections, appoint a member of the Board as acting mayor in his/her absence, and to direct personnel in the case of emergency. The mayor serves a four-year term and is limited to two successive terms. If the mayor dies or resigns, the President of the Board of Supervisors assumes the office as acting mayor. This has occurred twice since the 1970s: Dianne Feinstein became acting mayor after the assassination of George Moscone in 1978, and London Breed became acting mayor following the death of Ed Lee from a heart attack in 2017. The current mayor is London Breed. Board of Supervisors The legislative body is composed of the 11-member Board of Supervisors which acts as both a board of supervisors and a city council, with "[a]ll rights and powers of a City and County which are not vested in another officer or entity" by the charter. The Board of Supervisors is headed by a president and is responsible for passing laws and budgets. The members of the Board of Supervisors are elected as representatives of specific districts within the city. Other elected officers In addition, there are other citywide elected officers of San Francisco: Departments and