question: Who is Prince Koreyasu's paternal grandfather?
context: [["Prince Munetaka", ["Prince Munetaka (\u5b97\u5c0a\u89aa\u738b) (December 15, 1242 \u2013 September 2, 1274) was the sixth \"sh\u014dgun\" of the Kamakura shogunate of Japan who reigned from 1252 to 1266.", "He was the first son of the Emperor Go-Saga and replaced the deposed Fujiwara no Yoritsugu as \"sh\u014dgun\" at the age of ten.", "He was a puppet ruler controlled by the H\u014dj\u014d clan regents.", "The deposed \"sh\u014dgun\" became a Buddhist monk in 1272.", "His priestly name was Gy\u014dsh\u014d.", "He was a writer of Waka poetry."]], ["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 Westley", ["Rev. John Westley( 1636 \u2013 78) was an English nonconformist minister.", "He was the grandfather of John Wesley( founder of Methodism)."]], ["Abd al-Muttalib", ["Abd al- Muttalib Shaybah ibn Hashim( c. 497 \u2013 578) was the grandfather of Islamic prophet Muhammad."]], ["Guillaume Wittouck", ["Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.", "He was the Grandfather of industrialist Paul Wittouck."]], ["Prince Koreyasu", ["Prince Koreyasu (\u60df\u5eb7\u89aa\u738b) (May 26, 1264 \u2013 November 25, 1326; reigned 1266\u20131289) was the seventh \"sh\u014dgun\" of the Kamakura shogunate of Japan.", "He was the nominal ruler controlled by the H\u014dj\u014d clan regents.", "Prince Koreyasu was the son of Prince Munetaka who was the sixth \"sh\u014dgun\".", "At age 25, the deposed \"sh\u014dgun\" became a Buddhist monk.", "His priestly name was Ono-no miya."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["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."]], ["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."]], ["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."]]]
supporting_facts: [["Prince Koreyasu", 2], ["Prince Munetaka", 1]]
evidences: [["Prince Koreyasu", "father", "Prince Munetaka"], ["Prince Munetaka", "father", "Emperor Go-Saga"]]
answer: Emperor Go-Saga