Question: Who is the northwestern  neighbor of the country that boarders Iran on the northeast?

full_context: Document 1: Geography of Azerbaijan: Azerbaijan is situated in the Caucasus region of Eurasia. Three physical features dominate Azerbaijan: the Caspian Sea, whose shoreline forms a natural boundary to the east; the Greater Caucasus mountain range to the north; and the extensive flatlands at the country's center. About the size of Portugal or the state of Maine, Azerbaijan has a total land area of approximately 86,600 square kilometers, less than 1% of the land area of the former Soviet Union. Of the three Transcaucasian states, Azerbaijan has the greatest land area. Special administrative subdivisions are the Nakhchivan Autonomous Republic, which is separated from the rest of Azerbaijan by a strip of Armenian territory, and the Nagorno-Karabakh Autonomous Region, entirely within Azerbaijan. (The status of Nagorno-Karabakh was under negotiation in 1994.) Located in the region of the southern Caucasus Mountains, Azerbaijan borders the Caspian Sea to the east, Georgia and Russia to the north, Iran to the south, and Armenia to the southwest and west. A small part of Nakhchivan also borders Turkey to the northwest. The capital of Azerbaijan is the ancient city of Baku, which has the largest and best harbor on the Caspian Sea and has long been the center of the republic's oil industry.
Document 2: Geography of Kazakhstan: Kazakhstan is located in Central Asia and Eastern Europe at . With an area of about 2,724,800 square kilometers, Kazakhstan is more than twice the combined size of the other four Central Asian states, or about twice the size of Alaska. The country borders Turkmenistan, Uzbekistan, and Kyrgyzstan to the south; Russia to the north; Russia and the Caspian Sea to the west; and China's Xinjiang Uygur Autonomous Region to the east.
Document 3: Persian language: Persian ( or ), also known by its endonym Farsi (فارسی "fārsi " ] ) or Parsi (پارسی "Pārsi "), is one of the Western Iranian languages within the Indo-Iranian branch of the Indo-European language family. It is primarily spoken in Iran, Afghanistan (officially known as "Dari" since 1958), and Tajikistan (officially known as "Tajiki" since the Soviet era), and some other regions which historically were Persianate societies and considered part of Greater Iran. It is written in the Persian alphabet, a modified variant of the Arabic script.
Document 4: Turkmenistan: Turkmenistan ( or ; Turkmen: Türkmenistan/Түркменистан/توركمنستان , ), formerly known as Turkmenia, is a country in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north and east, Afghanistan to the southeast, Iran to the south and southwest, and the Caspian Sea to the west.
Document 5: Kyrgyzstan: Kyrgyzstan (Kyrgyz: Кыргызстан , "Qırğızstan", قىرعىزستان, (] ); Russian: Киргизия , "Kirgizija"), officially the Kyrgyz Republic (Kyrgyz: Кыргыз Республикасы , "Qırğız Respublikası", قىرعىز رەسپۇبلىکاسى; Russian: Кыргызская Республика "Kyrgyzskaja Respublika"), formerly known as Kirghizia or Kirgizia, is a country in Central Asia. Kyrgyzstan is a landlocked country with mountainous terrain. It is bordered by Kazakhstan to the north, Uzbekistan to the west and southwest, Tajikistan to the southwest and China to the east. Its capital and largest city is Bishkek.
Document 6: Tajikistan: Tajikistan ( , , or ; Тоҷикистон ] ; Russian: Таджикистан ), officially the Republic of Tajikistan (Tajik: Ҷумҳурии Тоҷикистон , "Çumhuriji Toçikiston/Jumhuriyi Tojikiston", جمهوری تاجیکستان, Russian: Республика Таджикистан ), also unofficially spelled as Tadzhikistan, is a mountainous, landlocked country in Central Asia with an estimated population of /1e6 round 1 million people as of , and an area of 143100 km2 . It is bordered by Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east. Pakistan lies to the south, separated by the narrow Wakhan Corridor. Traditional homelands of Tajik people included present-day Tajikistan, Afghanistan and Uzbekistan.
Document 7: Afghanistan: Afghanistan ( ; Pashto/Dari: , Pashto: "Afġānistān" ] , Dari: "Afġānestān" ] ), officially the Islamic Republic of Afghanistan, is a landlocked country located within South Asia and Central Asia. The country has a population of /1e6 round 0 million, making it the 42nd most populous country in the world. Afghanistan is bordered by Pakistan in the south and east; Iran in the west; Turkmenistan, Uzbekistan, and Tajikistan in the north; and China in the far northeast. Its territory covers 652,000 km2 , making it the 41st largest country in the world.
Document 8: Persian Gulf: The Persian Gulf (Persian: خلیج فارس‎ , "Xalij-e Fârs ", 'Gulf of Fars' ‎ ) is a mediterranean sea in Western Asia. The body of water is an extension of the Indian Ocean (Gulf of Oman) through the Strait of Hormuz and lies between Iran to the northeast and the Arabian Peninsula to the southwest. The Shatt al-Arab river delta forms the northwest shoreline.
Document 9: Supreme Leader of Iran: The Supreme Leader of Iran (Persian: رهبر معظم ایران‎ , "rahbar-e mo'azzam-e irān " ‎ ), also called the Supreme Leader of the Islamic Revolution (رهبر معظم انقلاب اسلامی , "rahbar-e mo'azzam-e enghelāb-e eslāmi "), officially in Iran, called the Supreme Leadership Authority (مقام معظم رهبری , "maqām mo'azzam rahbari "), is the head of state and highest ranking political and religious authority in the Islamic Republic of Iran. The armed forces, judicial system, state television, and other key governmental organizations are under the control of the Supreme Leader of Iran. The current longtime Supreme Leader of Iran, Ali Khamenei, has been issuing decrees and making the final decisions on economy, environment, foreign policy, education, national planning, and everything else in Iran. Khamenei also makes the final decisions on the amount of transparency in elections in Iran, and has fired and reinstated Presidential cabinet appointments. Iran’s regional policy is directly controlled by the office of the Supreme Leader with the Ministry of Foreign Affairs’ task limited to protocol and ceremonial occasions. All of Iran’s ambassadors to Arab countries, for example, are chosen by the Quds Corps, which directly reports to the Supreme Leader.
Document 10: Turan Depression: The Turan Depression, Turan Lowland or Turanian Basin is a low-lying desert basin region stretching from southern Turkmenistan through Uzbekistan to Kazakhstan. The lowland region lies to the east of the Caspian Sea and southeast of the Aral Sea in the vast Aral–Caspian Depression but extends to parts above sea level as well. It is one of the largest expanses of sand in the world. On average, the region receives less than 15 inches (381mm) of rainfall per year. The Kara Kum desert lies at the southern portion of the Turan Lowlands.
Document 11: Turkmenistan State News Agency: Turkmenistan State News Agency (in Turkmen: Türkmen döwlet habarlar agenligi ), sometimes shortened to TDH (Russian: ТДХ ), is the largest and only news agency in Turkmenistan. TDH headquarters are in Bitarap Turkmenistan Avenue, Ashgabat. The agency publishes news and analysis of the socio-political, socio-economic, cultural and sporting life of the state in Turkmen, Russian and English languages. Agency specialists are engaged in the development, technical and information support, and promotion of web sites relating to the culture of Turkmenistan. The current editor-in-chief of TDH is Bekdurdy Amansaryev
Document 12: Uzbekistan: Uzbekistan ( , ), officially the Republic of Uzbekistan (Uzbek: "Oʻzbekiston Respublikasi" , Ўзбекистон Республикаси , وزبېکىستان رېسپۇبلیکەسی ; Russian: Республика Узбекистан ), is one of only two doubly landlocked countries in the world. Located in Central Asia, it is a secular, unitary constitutional republic, comprising 12 provinces, one autonomous republic, and a capital city. Uzbekistan is bordered by five landlocked countries: Kazakhstan to the north; Tajikistan to the southeast; Kyrgyzstan to the northeast; Afghanistan to the south; and Turkmenistan to the southwest.
Document 13: Tourism in Iran: Tourism in Iran is diverse, providing a range of activities from hiking and skiing in the Alborz and Zagros mountains, to beach holidays by the Persian Gulf and the Caspian Sea. The Iranian government has been making concerted efforts to attract tourists to the various destinations in the country and arrivals have increased during the past years. Kish Island alone attracts around 1 million visitors per year, the majority of whom are Iranian but also this its attractive for non-Iranian Muslim who like to have beach holiday with Islamic style that let men and women use separate beaches .
Document 14: Iran Air: Iran Air, branded as The Airline of the Islamic Republic of Iran (Persian: هواپیمايی جمهوری اسلامی ایران‎ ‎ "Havâpeymâyiye Jomhuriye Eslâmiye Irân"), is the national flag carrier airline of Iran headquartered on the grounds of Mehrabad Airport in Tehran. Tehran-Imam Khomeini and Tehran-Mehrabad are its main bases for international and domestic flights. As of August 2017, it operates scheduled services to 59 destinations in Asia and Europe. The airline has a subsidiary for cargo services, called Iran Air Cargo, that operates scheduled and charter services.
Document 15: Iran: Iran (Persian: ایران‎ ‎ "Irān " ] ), also known as Persia ( ), officially the Islamic Republic of Iran (Persian: جمهوری اسلامی ایران‎ ‎ "Jomhuri-ye Eslāmi-ye Irān " ), is a sovereign state in Western Asia. With over 79.92 million inhabitants (as of August 2017 ), Iran is the world's 18th-most-populous country. Comprising a land area of 1648195 km2 , it is the second-largest country in the Middle East and the 17th-largest in the world. Iran is bordered to the northwest by Armenia, the "de facto" independent Republic of Artsakh, the Republic of Azerbaijan, and the Azerbaijani exclave of Nakhchivan; to the north by the Caspian Sea; to the northeast by Turkmenistan; to the east by Afghanistan and Pakistan; to the south by the Persian Gulf and the Gulf of Oman; and to the west by Turkey and Iraq. The country's central location in Eurasia and Western Asia, and its proximity to the Strait of Hormuz, give it geostrategic importance. Tehran is the country's capital and largest city, as well as its leading economic and cultural center.
ground_truth: Kazakhstan