question: What is the date of death of Yolanda Of Vianden's mother?
context: [["Marie de Namur", ["Marie of Namur, also known as Marie de Namur or Maria van Dampierre.", "Her titles were\" Gr\u00e4fin von Vianden\", from her first marriage and\" Dame de Pierrepont\", from her second marriage to, Theobald of Bar.", "Born in 1322 to John I of Namur and his wife Marie of Artois.", "She had three sisters, including Blanche of Namur, Queen consort of Sweden and Norway, and seven brothers.", "In 1335/ 36, she married her first husband, Henry II, Graf of Vianden, son of Philip II, Graf of Vianden and his first wife Lucia von der Neuerburg.", "Henry was murdered at Famagusta in September 1337.", "In c. 1337, she gave birth to Maria of Vianden her first daughter from her marriage to Henry II, Graf of Vianden.", "Her second marriage in 1340( dispensation 9 September 1342) was to her father's second cousin, Theobald of Bar, Seigneur de Pierrepont, son of Erard of Bar, Seigneur de Pierrepont et d'Ancerville( himself son of Theobald II of Bar), and his wife Isabelle of Lorraine( daughter of Theobald II, Duke of Lorraine).", "This marriage produced two daughters, Yolande de Bar( b. c 1343 \u2013 d. c 1410) and Elisabeth de Bar( b. c 1345 \u2013 d. before 11 May 1411).", "Marie died somewhere before 29 October 1353/ 57."]], ["Yolanda of Vianden", ["Mother Yolanda (or Yolande, Iolanda) of Vianden, O.P., (1231\u20131283) was the youngest daughter of Count Henry I of Vianden and Margaret, Marchioness of Namur.", "She joined the Dominican monastery in Marienthal, Luxembourg, against the wishes of her parents when she was very young.", "She later became its devout prioress and is now a legend in the history of that nation."]], ["Etan Boritzer", ["Etan Boritzer( born 1950) is an American writer of children \u2019s literature who is best known for his book\" What is God?\" first published in 1989.", "His best selling\" What is?\" illustrated children's book series on character education and difficult subjects for children is a popular teaching guide for parents, teachers and child- life professionals.", "Boritzer gained national critical acclaim after\" What is God?\" was published in 1989 although the book has caused controversy from religious fundamentalists for its universalist views.", "The other current books in the\" What is?\" series include", "What is Love?,", "What is Death?,", "What is Beautiful?,", "What is Funny?,", "What is Right?,", "What is Peace?,", "What is Money?,", "What is Dreaming?,", "What is a Friend?,", "What is True?,", "What is a Family?,", "What is a Feeling?\"", "The series is now also translated into 15 languages.", "Boritzer was first published in 1963 at the age of 13 when he wrote an essay in his English class at Wade Junior High School in the Bronx, New York on the assassination of John F. Kennedy.", "His essay was included in a special anthology by New York City public school children compiled and published by the New York City Department of Education.", "Boritzer now lives in Venice, California and maintains his publishing office there also.", "He has helped numerous other authors to get published through\" How to Get Your Book Published!\" programs.", "Boritzer is also a yoga teacher who teaches regular classes locally and guest- teaches nationally.", "He is also recognized nationally as an erudite speaker on\" The Teachings of the Buddha.\""]], ["Thomas Scott (diver)", ["Thomas Scott( 1907- date of death unknown) was an English diver."]], ["Princess Yolanda of Savoy", ["Princess Yolanda of Savoy (1 June 1901 \u2013 16 October 1986) was the eldest daughter of King Victor Emmanuel III of Italy."]], ["Otto II of Nassau", ["Otto II of Nassau( \u2013 1351) was a German nobleman.", "He was a Count of Nassau- Dillenburg in Siegen and Dillenburg, and was a son of Count Heinrich of Nassau and Adelheid of Heinsberg.", "Otto married Adelheid of Vianden, daughter of Philip of Vianden and Adelheid of Arnsberg.", "They had four children:"]], ["Theodred II (Bishop of Elmham)", ["Theodred II was a medieval Bishop of Elmham.", "The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997."]], ["Geoffrey I of Vianden", ["Geoffrey I of Vianden\" 7th duke of Vianden 1273- 1310\"( 1310) was a son to duke Filips I of Vianden and Mary of Brabant- Perwez.", "He succeeded to his father in 1273 in Vianden.", "Geoffrey married Aleidis of Oudenaarde( 1260- 1305) and Lutgardis van Ligny and fathered:"]], ["Bill Smith (footballer, born 1897)", ["William Thomas Smith( born 9 April 1897, date of death unknown) was an English professional footballer."]], ["Margaret, Marchioness of Namur", ["Margaret, Marchioness of Namur (c. 1194 \u2013 17 July 1270) was ruling Marchioness of Namur in 1229-1237.", "She was the daughter of Peter II of Courtenay and Yolanda of Flanders."]]]
supporting_facts: [["Yolanda of Vianden", 0], ["Margaret, Marchioness of Namur", 0]]
evidences: [["Mother Yolanda (or Yolande, Iolanda) of Vianden", "mother", "Margaret, Marchioness of Namur"], ["Margaret, Marchioness of Namur", "date of death", "17 July 1270"]]
answer: 17 July 1270