question: Who is Walter Maule's paternal grandfather?
context: [["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]], ["Fujiwara no Nagara", [", also known as Fujiwara no Nagayoshi, was a Japanese statesman, courtier and politician of the early Heian period.", "He was the grandfather of Emperor Y\u014dzei."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["Henry Bryant (naturalist)", ["Henry Bryant( May 12, 1820 \u2013 February 2, 1867) was an American physician and naturalist.", "He was the grandfather of Henry Bryant Bigelow."]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Guillaume Wittouck", ["Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.", "He was the Grandfather of industrialist Paul Wittouck."]], ["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."]], ["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."]], ["Walter Maule", ["Walter Maule was the son and heir of Sir Henry Maule, Baron of Panmure and Benvie, and Margaret, daughter of Sir William Hay of Locherworth.", "He was warden of Kildrummy Castle in the reign of David II.", "The name of Walter's spouse is unknown, but he left two sons, William and Henry.", "William was named successor to the baronies of Panmure and Benvie on his father's death in 1348."]], ["Henry Maule", ["Sir Henry Maule was the son and heir of Sir William Maule, Baron of Panmure and Benvie and Ethana de Vallibus, daughter of John Vaux, Lord of Dirleton.", "William succeeded as Baron on his father's death and was married to Margaret Hay, daughter of Sir William Hay of Locherworth.", "He was knighted by Robert I of Scotland for his services during the First War of Independence.", "He left three sons: Walter, who succeeded him as Baron of Panmure and Benvie; William; Peter; and a daughter, Christian."]]]
supporting_facts: [["Walter Maule", 0], ["Henry Maule", 0]]
evidences: [["Walter Maule", "father", "Henry Maule"], ["Henry Maule", "father", "Sir William Maule"]]
answer: Sir William Maule