Passage: All members of the executive and legislative branches are directly elected. Judges and other judicial officials are appointed after passing entry exams. For most of its democratic history, Brazil has had a multi-party system, proportional representation. Voting is compulsory for the literate between 18 and 70 years old and optional for illiterates and those between 16 and 18 or beyond 70.Together with several smaller parties, four political parties stand out: Workers' Party (PT), Brazilian Social Democracy Party (PSDB), Brazilian Democratic Movement (MDB) and Democrats (DEM). Fifteen political parties are represented in Congress. It is common for politicians to switch parties, and thus the proportion of congressional seats held by particular parties changes regularly. Almost all governmental and administrative functions are exercised by authorities and agencies affiliated to the Executive.

Question: How many different parties make up Brazil's congress?
Fifteen