Given the question: Information:  - Poland, officially the Republic of Poland, is a country in Central Europe, situated between the Baltic Sea in the north and two mountain ranges (the Sudetes and Carpathian Mountains) in the south. Bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine and Belarus to the east; and the Baltic Sea, Kaliningrad Oblast (a Russian exclave) and Lithuania to the north. The total area of Poland is , making it the 69th largest country in the world and the 9th largest in Europe. With a population of over 38.5 million people, Poland is the 34th most populous country in the world, the 8th most populous country in Europe and the sixth most populous member of the European Union. Poland is a unitary state divided into 16 administrative subdivisions, and its capital and largest city is Warsaw. Other metropolises include Kraków, Wrocaw, Pozna, Gdask and Szczecin.  - The President of the Republic of Poland (shorter form: "Prezydent RP") is the Polish head of state. His or her rights and obligations are determined in the Constitution of Poland. The president heads the executive branch. In addition the president has a right to dissolve the parliament in certain cases, and represents Poland in the international arena.  - The incumbent is the current holder of a political office. This term is usually used in reference to elections, in which races can often be defined as being between an incumbent and non-incumbent(s). For example, in the 2012 United States presidential election, Barack Obama was the incumbent, because he had been the president in the previous term while the election sought to determine the president for the current term. A race without an incumbent is referred to as an open seat.  - Barack Hussein Obama II (; born August 4, 1961) is an American politician who served as the 44th President of the United States from 2009 to 2017. He was the first African American to serve as president, as well as the first born outside the contiguous United States. He previously served in the U.S. Senate representing Illinois from 2005 to 2008, and in the Illinois State Senate from 1997 to 2004.  - The European Union (EU) is a political and economic union of member states that are located primarily in Europe. It has an area of , and an estimated population of over 510 million. The EU has developed an internal single market through a standardised system of laws that apply in all member states. EU policies aim to ensure the free movement of people, goods, services, and capital within the internal market, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries, and regional development. Within the Schengen Area, passport controls have been abolished. A monetary union was established in 1999 and came into full force in 2002, and is composed of 19 EU member states which use the euro currency.  - Aleksander Kwaniewski (born 15 November 1954) is a Polish politician and journalist. He served as the President of Poland from 1995 to 2005. He was born in Biaogard, and during communist rule he was active in the Socialist Union of Polish Students and was the Minister for Sport in the communist government in the 1980s. After the fall of communism he became a leader of the left-wing Social Democracy of the Republic of Poland, successor to the former ruling Polish United Workers' Party, and a co-founder of the Democratic Left Alliance.  - The 2000 Polish presidential election took place in Poland on 8 October 2000 . Incumbent President Aleksander Kwaniewski was easily re-elected in the first round after winning more than 50 % of the votes .  - Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south. Slovakia's territory spans about and is mostly mountainous. The population is over 5 million and comprises mostly ethnic Slovaks. The capital and largest city is Bratislava. The official language is Slovak, a member of the Slavic language family.  - A unitary state is a state governed as a single power in which the central government is ultimately supreme and any administrative divisions (sub-national units) exercise only the powers that the central government chooses to delegate. The majority of states in the world have a unitary system of government. Of the 193 UN member states, 165 of them are governed as unitary states.    Given the information, choose the subject and object entities that have the relation of 'office contested'.
The answer is:
polish presidential election , president of poland