The capital of Brandenburg is Potsdam, a city of seven letters. It is located on the Havel River and is known for its many parks and palaces. The Oder River, which forms part of the border between Germany and Poland, is four letters long. Johann Sebastian BACH, the famous composer, was born in the city of Eisenach, which is also four letters long. Six is three letters long and is the number of states that make up the Federal Republic of Germany. Drei is four letters long and is the German word for three.