The Council of States is the upper house of the Federal Assembly of Switzerland, with the National Council being the lower house. It comprises 46 members. Twenty of the country's cantons are represented by two Councillors each. Six cantons, traditionally called "half cantons", are represented by one Councillor each for historical reasons. These are Obwalden, Nidwalden, Basel-Stadt, Basel-Landschaft, Appenzell Ausserrhoden and Appenzell Innerrhoden. The Councillors serve for four years, and are not bound in their vote to instructions from the cantonal authorities. Electoral system Under the Swiss Federal Constitution, the mode of election to the Council of States is left to the cantons, the provision being that it must be a democratic method. All cantons now provide for the councilors to be chosen by popular election, although historically it was typically the cantons' legislatures that elected representatives to Bern. Despite this freedom the Constitution provides the cantons, with the exception of the cantons of and (which use proportional representation to elect their councilors), councilors are elected through an up to two-round system of voting. In the first round of voting, candidates must obtain an absolute majority of the vote in order to be elected. If no candidate receives an absolute majority in the first round of voting then a second round is held in which a simple plurality is sufficient to be elected. The top two finishing candidates in the second round are elected. However, eligibility to vote varies according to the applicable cantonal law. One notable variation is that qualified foreigners may vote in Neuchâtel and Jura, and the minimum voting age is 16 in Glarus. In all the cantons except the councillors are elected concurrently with the members of the National Council. In the representative is elected by the popular assembly () during the April before the national vote. Working languages In debates, councilors can choose any of the federal languages, usually the one they are most proficient in: German, French, Italian, or Romansh. German (High German) and French are the most frequently used. While the National Council offers simultaneous interpretation for German and French (since 1960) and Italian (since about 2000), the Council of States offers none. Councilors are expected to understand at least two languages, German and French. Voting Issues before the council pass with a majority of the votes cast. The president of the council typically does not vote, unless there is a tie. In