question: Who is Prince Welf Ernst Of Hanover's maternal grandfather?
context: [["Prince Ernst August of Hanover (born 1983)", ["Ernst August, Hereditary Prince of Hanover( born 19 July 1983) is the eldest child of Ernst August, Prince of Hanover( head of the ancient House of Welf which once ruled the Kingdom of Hanover), and his former wife Chantal Hochuli."]], ["Princess Friederike of Hanover", ["Princess Friederike of Hanover( born 15 October 1954 at Salem, Baden- W\u00fcrttemberg, Germany) is a member of the Royal House of Hanover.", "She is a niece of Prince Philip, Duke of Edinburgh."]], ["Turiya Hanover", ["Turiya Hanover, aka\" Wibke, Princess Welf Ernst of Hanovern\u00e9e\" van Gunsteren( born 1948, L\u00fcbeck), is a German psychotherapist and wife of the late Prince Welf of Hanover of the House of Hanover.", "She has published some guided meditations.", "Wibke was born as daughter of Ursula Schmidt- Prange and Dr. Hans- Daniel Christians, a physician.", "Her mother then married Harry van Gunsteren and the whole young family took van Gunsteren as surname, including the step- daughter Wibke.", "In 1969 Wibke married Prince Welf of Hanover, a first cousin of Prince Ernst August of Hanover, the current head of the House of Guelf as well as a first cousin of Charles, Prince of Wales, the current heir to the throne of the British Commonwealth.", "In 1970, they had a child, Princess Saskia of Hanover, currently known as Mrs Saskia Hooper.", "In 1973 Wibke started to work as Gestalt therapist.", "In 1975 she and her husband Welf moved to India, having become sannyasins of Osho and taken the names\" VimalkirtiSpotless splendour\") and Wibke\" TuriyaSpiritual love\", Sk. \u0924\u0941\u0930\u0940\u092f' The Fourth').", "Along with their five- year- old daughter Tania Saskia they moved to Poona, India to live with Osho.", "Welf died at the age of 33 at a clinic in Poona from a cerebral haemorrhage after collapsing during a morning exercise session and becoming paralysed at the ashram.", "Although there are claims that they were divorced in 1979 there was no such divorce.", "They were married until Prince Welf died in 1981.", "Currently Turiya( Wibke) Hanover lives in Byron Bay, Australia.", "Turiya has published at least five guided meditations:"]], ["Thyra von Westernhagen", ["Thyra, Princess Heinrich of Hanover( n\u00e9e Thyra von Westernhagen; born 14 August 1973) is a German forester and landowner.", "As the wife of Prince Heinrich of Hanover, she is a princess of the House of Hanover."]], ["Chantal Hochuli", ["Chantal Hochuli, formerly Chantal, Princess of Hanover, Duchess of Brunswick and L\u00fcneburg( born 2 June 1955) is a Swiss socialite and heiress.", "She is the ex-wife of Ernst August, Prince of Hanover, the head of the German House of Hanover."]], ["Princess Sophie of Greece and Denmark", ["Princess Sophie of Greece and Denmark (26 June 1914 \u2013 24 November 2001) was the fourth child and youngest daughter of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg.", "The Duke of Edinburgh is her younger brother.", "Sophie was born at the villa Mon Repos on the island of Corfu in Greece."]], ["Prince Welf Ernst of Hanover", ["Prince Welf Ernst of Hanover", "(Welf Ernst August Andreas Philipp Georg Wilhelm Ludwig Berthold Prinz von Hannover), Duke of Brunswick-L\u00fcneburg (25 January 1947 \u2013 10 January 1981) was the eldest son of Prince George William of Hanover and his wife Princess Sophie of Greece and Denmark, sister of Prince Philip, Duke of Edinburgh.", "Welf was a first cousin of Charles, Prince of Wales.", "The prince used the name Welf Prinz von Hannover."]], ["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."]], ["Ekaterina Malysheva", ["Ekaterina, Hereditary Princess of Hanover( n\u00e9e Malysheva; born 30 July 1986) is a Russian fashion designer and filmmaker.", "She is the hereditary princess of the House of Hanover through her marriage to Ernst August, Hereditary Prince of Hanover."]], ["Alexandra Prinzessin von Hannover", ["Alexandra Prinzessin von Hannover( n\u00e9e\" Alexandra", "Sophie Cecilie Anna", "Maria Friederike Benigna Dorothea Prinzessin zu Ysenburg und B\u00fcdingen\"; 23 October 1937 \u2013 1 June 2015) was a German politician, philanthropist, and wife of Prince Welf Henry of Hanover.", "Hannover lastly served as a councilwoman representing the Niederrad district of Frankfurt on the Frankfurt City Council.", "She was a member of the Christian Democratic Union political party."]]]
supporting_facts: [["Prince Welf Ernst of Hanover", 1], ["Princess Sophie of Greece and Denmark", 0]]
evidences: [["Prince Welf Ernst of Hanover", "mother", "Princess Sophie of Greece and Denmark"], ["Princess Sophie of Greece and Denmark", "father", "Prince Andrew of Greece and Denmark"]]
answer: Prince Andrew of Greece and Denmark