question: Who is Peter The Younger's maternal grandfather?
context: [["Doamna Chiajna", ["Doamna Chiajna (1525\u20131588) was a Princess consort of Wallachia.", "She was married to Mircea the Shepherd.", "She was regent in Wallachia in 1559\u20131575.", "She was born as Ana in Poland as the daughter of prince Peter IV Rare\u0219, and married prince Mircea the Shepherd in 1545.", "She founded the first school in Romania: C\u00e2mpulung in 1552.", "After the death of her spouse in 1559, she became regent in Wallachia on behalf of her son Petru cel T\u00e2n\u0103r.", "She is described as an energetic, intelligent and gifted politician.", "In 1575, she was abducted by the Ottomans and deported to Aleppo in Syria.", "Last sourced report on 1588 and her resting place", "whereabouts remained unclear."]], ["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]], ["Kaya Alp", ["Kaya Alp was, according to Ottoman tradition, the son of K\u0131z\u0131l Bu\u011fa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertu\u011frul, and the great grandfather of the Ottoman Empire founder, Osman I."]], ["John Rufus", ["John Rufus( born c. AD 450)( also called John of Beth Rufina) was an anti-Chalcedonian priest of Antioch, a disciple of Peter the Iberian and an ecclesiastical historian who served as the bishop of Maiuma.", "He wrote the\" Plerophoriae\" and\" The life of Peter the Iberian\", the\" Commemoration of the death of Theodosius\" John was born in the province of Arabia around 450 AD and studied jurisprudence at the Law School of Beirut.", "He was ordained a priest in Antioch around 475 by Peter the Fuller.", "Upon the return to power of emperor Zeno and the expulsion of Peter the Fuller in 477, John moved to Palestine where he became a disciple of Peter the Iberian.", "Upon", "Peter the Iberian's death, the bishopric at his monastery of Maiuma passed on to Theodore of Ascalon whereas the\" Plerophoriae' names John Rufus as the bishop of the city."]], ["Grand Duchess Natalia Petrovna of Russia (1718\u20131725)", ["Grand Duchess Natalia Petrovna of Russia was the youngest daughter of Peter the Great and his second wife Catherine I."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["Peter the Younger", ["Peter the Younger (Romanian: \"Petru cel T\u00e2n\u0103r\")", "(1547 \u2013 19 August 1569) was the Voivode (Prince) of Wallachia between 25 September 1559 and 8 June 1568.", "The eldest son of Mircea the Shepherd and Doamna Chiajna, his named \"the Young\" because, at the moment of crowning, he was only 13."]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Prithvipati Shah", ["Prithvipati Shah( ?\u20131716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.", "He was the grandfather of Nara Bhupal Shah."]], ["Lindsey Hughes", ["Lindsey Hughes( 4 May 1949 \u2013 26 April 2007) was a British historian who studied seventeenth- and eighteenth- century Russia, especially the reign of Peter the Great.", "She wrote biographies of Peter and his predecessor Sophia Alekseyevna, as well as a more general work,\" Russia in the Age of Peter the Great\".", "She also wrote prolifically on art history."]]]
supporting_facts: [["Peter the Younger", 2], ["Doamna Chiajna", 3]]
evidences: [["Peter the Younger", "mother", "Doamna Chiajna"], ["Doamna Chiajna", "father", "Peter IV Rare\u0219"]]
answer: Peter IV Rareș