Input: Read this: Greece's rail network is estimated to be at 2,548 km. Rail transport in Greece is operated by TrainOSE, a subsidiary of the Hellenic Railways Organization (OSE). Most of the country's network is standard gauge (1,565 km), while the country also has 983 km of narrow gauge. A total of 764 km of rail are electrified. Greece has rail connections with Bulgaria, the Republic of Macedonia and Turkey. A total of three suburban railway systems (Proastiakos) are in operation (in Athens, Thessaloniki and Patras), while one metro system is operational in Athens with another under construction.
Question: Who runs the rail transport in Greece?

Output: TrainOSE


Input: Read this: A number of theories have been proposed regarding Avicenna's madhab (school of thought within Islamic jurisprudence). Medieval historian Ẓahīr al-dīn al-Bayhaqī (d. 1169) considered Avicenna to be a follower of the Brethren of Purity. On the other hand, Dimitri Gutas along with Aisha Khan and Jules J. Janssens demonstrated that Avicenna was a Sunni Hanafi. However, the 14th cenutry Shia faqih Nurullah Shushtari according to Seyyed Hossein Nasr, maintained that he was most likely a Twelver Shia. Conversely, Sharaf Khorasani, citing a rejection of an invitation of the Sunni Governor Sultan Mahmoud Ghazanavi by Avicenna to his court, believes that Avicenna was an Ismaili. Similar disagreements exist on the background of Avicenna's family, whereas some writers considered them Sunni, some more recent writers contested that they were Shia.
Question: Who's court did Avicenna join?

Output: unanswerable


Input: Read this: There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation inherent with AC, and on a railway this also reduces interference with signalling and communications and mitigates hypothetical EMF risks. DC also avoids the power factor problems of AC. Of particular interest to railroading is that DC can supply constant power with a single ungrounded wire. Constant power with AC requires three-phase transmission with at least two ungrounded wires. Another important consideration is that mains-frequency 3-phase AC must be carefully planned to avoid unbalanced phase loads. Parts of the system are supplied from different phases on the assumption that the total loads of the 3 phases will even out. At the phase break points between regions supplied from different phases, long insulated supply breaks are required to avoid them being shorted by rolling stock using more than one pantograph at a time. A few railroads have tried 3-phase but its substantial complexity has made single-phase standard practice despite the interruption in power flow that occurs twice every cycle. An experimental 6 kV DC railway was built in the Soviet Union.
Question: DC can supply variable power with a single underground what?

Output: unanswerable


Input: Read this: Public priests were appointed by the collegia. Once elected, a priest held permanent religious authority from the eternal divine, which offered him lifetime influence, privilege and immunity. Therefore, civil and religious law limited the number and kind of religious offices allowed an individual and his family. Religious law was collegial and traditional; it informed political decisions, could overturn them, and was difficult to exploit for personal gain. Priesthood was a costly honour: in traditional Roman practice, a priest drew no stipend. Cult donations were the property of the deity, whose priest must provide cult regardless of shortfalls in public funding – this could mean subsidy of acolytes and all other cult maintenance from personal funds. For those who had reached their goal in the Cursus honorum, permanent priesthood was best sought or granted after a lifetime's service in military or political life, or preferably both: it was a particularly honourable and active form of retirement which fulfilled an essential public duty. For a freedman or slave, promotion as one of the Compitalia seviri offered a high local profile, and opportunities in local politics; and therefore business. During the Imperial era, priesthood of the Imperial cult offered provincial elites full Roman citizenship and public prominence beyond their single year in religious office; in effect, it was the first step in a provincial cursus honorum. In Rome, the same Imperial cult role was performed by the Arval Brethren, once an obscure Republican priesthood dedicated to several deities, then co-opted by Augustus as part of his religious reforms. The Arvals offered prayer and sacrifice to Roman state gods at various temples for the continued welfare of the Imperial family on their birthdays, accession anniversaries and to mark extraordinary events such as the quashing of conspiracy or revolt. Every January 3 they consecrated the annual vows and rendered any sacrifice promised in the previous year, provided the gods had kept the Imperial family safe for the contracted time.
Question: What was the term of office for a priest in Rome?

Output:
lifetime