question: Who is the paternal grandfather of William Iv, Count Of Ponthieu?
context: [["William IV, Count of Nevers", ["William IV, Count of Nevers,( c. 1130 \u2013 Acre, 24 October 1168) Count of Nevers, Auxerre and Tonnerre( 1161 \u2013 1168)."]], ["William, Margrave of Meissen", ["William IV, Count of Weimar( died 1062) was Margrave of Meissen from 1046 until his death."]], ["William IV, Count of Ponthieu", ["William IV Talvas (1179 \u2013 October 4, 1221) was William III, Count of Ponthieu and William IV (of the house of Belleme/Montgomery).", "He was Count of Ponthieu, ruler of a small province in northern France that fell under the suzerainty of the dukes of Normandy (later also kings of England)", "since at least the mid 11th century.", "He was son and heir of John I, Count of Ponthieu (died 1191) by his third wife Beatrice de St Pol."]], ["Guy I, Count of Ponthieu", ["Guy I of Ponthieu( also known in the Bayeux Tapestry as Wido) was born sometime in the mid to late 1020s and died 13 October 1100.", "He succeeded his brother Enguerrand as Count of Ponthieu."]], ["Agnes, Countess of Ponthieu", ["Agnes of Ponthieu( c. 1080 \u2013 aft. 1105) was ruling Countess of Ponthieu from 1100.", "She was the daughter of Count Guy I of Ponthieu.", "Enguerrand, the son of Count Guy, died at a youthful age.", "Guy then made his brother Hugh heir presumptive, but he also died before Guy( died 1100).", "Agnes became count Guy's heiress, and was married to Robert of Bell\u00eame.", "Their son William III of Ponthieu succeeded to the county of Ponthieu after the death of Agnes( between 1105 and 1111), and the imprisonment of his father in 1112."]], ["William III, Count of Ponthieu", ["William III of Ponthieu( \u2013 1172) also called William( II; III) Talvas.", "He was seigneur de Montgomery in Normandy and Count of Ponthieu."]], ["Guy II of Ponthieu", ["Guy II of Ponthieu( \u2013 25 December 1147) was the son of William III of Ponthieu and Helie of Burgundy."]], ["John I, Count of Looz", ["John I (Jean) (d. 1278 or 1279), Count of Looz and Count of Chiny, eldest son of Arnold IV, Count of Looz and Chiny, and Jeanne, Countess of Chiny.", "He succeeded his father in 1272 or 1273, as the Count of Looz and Chiny.", "Virtually nothing is known about his reign.", "He first married, in 1258, Matilda, daughter of William IV, Count of J\u00fclich, and Matilda of Gelderland.", "Their children were:", "Widowed, he married secondly, in 1269, Isabelle de Conde (d. after 1280), daughter of Jacques, Seigneur of Conde and Bailleul, and his wife Agnes of R\u0153ulx.", "Their children were::\nUpon his death, he was succeeded as Count of Chiny by his brother Louis, and as Count of Looz by his son Arnold."]], ["John I, Count of Ponthieu", ["John I of Ponthieu (\u2013 1191) was the son of Guy II of Ponthieu and succeeded him as Count of Ponthieu in 1147."]], ["Gisela of France, Countess of Ponthieu", ["Gis\u00e8le of France( ca. 968 \u2013 1002) was the daughter of Hugh Capet and Adelaide of Aquitaine.", "She married Count Hugh I of Ponthieu around 994.", "Her children by Hugh included Enguerrand I of Ponthieu and Guy of Ponthieu."]]]
supporting_facts: [["William IV, Count of Ponthieu", 3], ["John I, Count of Ponthieu", 0]]
evidences: [["William IV, Count of Ponthieu", "father", "John I, Count of Ponthieu"], ["John I, Count of Ponthieu", "father", "Guy II of Ponthieu"]]
answer: Guy II of Ponthieu