question: Who is Ottaviano Riario's maternal grandfather?
context: [["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."]], ["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]], ["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."]], ["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 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"]], ["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."]], ["John Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["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."]], ["Ottaviano Riario", ["Ottaviano Riario (September 1479 \u2013 1523) was an Italian condottiero and Lord of Imola and Forl\u00ec.", "Despite his nominal leadership, the real power lay with his mother Caterina Sforza."]], ["Caterina Sforza", ["Caterina Sforza (1463 \u2013 28 May 1509) was an Italian noblewoman along with the Countess of Forl\u00ec and Lady of Imola, firstly with her husband Girolamo Riario, and after his death as a regent of her son Ottaviano.", "Caterina was the illegitimate daughter of Galeazzo Maria Sforza, Duke of Milan and Lucrezia, the wife of the courtier Gian Piero Landriani, a close friend of the Duke.", "She was raised in the refined Milanese court.", "The descendant of a dynasty of noted condottieri, from an early age, Caterina distinguished herself through her bold and impetuous actions taken to safeguard her possessions from possible usurpers and to defend her dominions from attack, when they were involved in political intrigues.", "In her private life Caterina was devoted to various activities, including experiments in alchemy and a love of hunting and dancing.", "She had many children, but", "only the youngest, Captain Giovanni dalle Bande Nere, inherited his mother's forceful, militant personality.", "Caterina's resistance to Cesare Borgia meant she had to face his fury and imprisonment.", "Once she gained her freedom in Rome, she led a quiet life in Florence.", "In the final years of her life, she confided to a monk: \"Se io potessi scrivere tutto, farei stupire", "il mondoIf", "I could write everything that happened, I would shock the world\")."]]]
supporting_facts: [["Ottaviano Riario", 1], ["Caterina Sforza", 1]]
evidences: [["Ottaviano Riario", "mother", "Caterina Sforza"], ["Caterina Sforza", "father", "Galeazzo Maria Sforza"]]
answer: Galeazzo Maria Sforza