What are the names of the two leading largest political parties in Germany?

There are 12 main political parties that are recognized in Germany. The main political parties are the Social Democratic Party of Germany, also known as SPD, and the German Christian Democratic Union, also known as CDU. Of the 16 states in Germany, 14 of them fall under one of these two parties. Nine of the German states are run by the SPD and the remaining five are run by CDU. Baden-Wuerttemburg is run by the Green Party, locally referred to as Buendnis 90 or Die Gruenen. The other state with a different political representation is Thueringen and their party is Die Linke, or The Left. The current President of Germany is Joachim Gauck. While he is not affiliated with any political party, he has the highest position of power in Germany. The next person of power is the chancellor and currently Angela Merkel holds that position.