question: Who is Lulach's maternal grandfather?
context: [["Gruoch of Scotland", ["Gruoch ingen Boite  was a Scottish queen, the daughter of Boite mac Cin\u00e1eda, son of Cin\u00e1ed III.", "She is most famous for being the wife and queen of MacBethad mac Findla\u00edch (Macbeth).", "The dates of her life are uncertain."]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Henry Krause", ["Henry J.\" Red\" Krause, Jr.( August 28, 1913 \u2013 February 20, 1987) was an American football offensive lineman in the National Football League for the Brooklyn Dodgers and the Washington Redskins.", "He played college football at St. Louis University.", "He is the grandfather of Jennifer Krause", "He is the great grandfather of Payton Hoeing"]], ["Zhao Shoushan", ["Zhao Shoushan( 12 November 1894 \u2013 20 June 1965) was a KMT general and later Chinese Communist Party politician.", "He is the grandfather of Zhao Leji."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["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 Mackay (poet)", ["John Mackay( 1656\u20131754), known as( The Blind Piper), was a Scottish Gaelic poet and composer, and the grandfather of William Ross."]], ["Fred Le Deux", ["Frederick\" Fred\" Le Deux( born 4 December 1934) was an Australian rules footballer who played with Geelong in the Victorian Football League( VFL).", "He is the grandfather of Tom Hawkins."]], ["Lulach", ["Lulach mac Gille Coemg\u00e1in", "(Modern Gaelic: \"Lughlagh mac Gille Chomghain\", known in English simply as Lulach, and nicknamed Tairbith, \"the Unfortunate\" and Fatuus, \"the Simple-minded\" or \"the Foolish\"; before 1033 \u2013 17 March 1058) was King of Scots between 15 August 1057 and 17 March 1058.", "Lulach was the son of Gruoch of Scotland, from her first marriage to Gille Coemg\u00e1in, Mormaer of Moray, and thus the stepson of Macbeth (Mac Bethad mac Findla\u00edch).", "Following the death of Macbeth at the Battle of Lumphanan on 15 August 1057, the king's followers placed Lulach on the throne.", "He has the distinction of being the first king of Scotland of whom there are coronation details available: he was crowned, probably on 8 September 1057 at Scone.", "Lulach appears to have been a weak king, as his nicknames suggest, and ruled only for a few months before being assassinated and usurped by Malcolm III.", "Lulach's son M\u00e1el Snechtai was Mormaer of Moray, while \u00d3engus of Moray was the son of Lulach's daughter.", "He is believed to be buried on Saint Columba's Holy Island of Iona in or around the monastery.", "The exact position of his grave is unknown."]]]
supporting_facts: [["Lulach", 2], ["Gruoch of Scotland", 0]]
evidences: [["Lulach", "mother", "Gruoch of Scotland"], ["Gruoch of Scotland", "father", "Boite mac Cin\u00e1eda"]]
answer: Boite mac Cináeda