question: Who is Stanisław Of Masovia's paternal grandfather?
context: [["Stanis\u0142aw of Masovia", ["Stanis\u0142aw of Masovia (pl: \"Stanis\u0142aw mazowiecki\"; 17 May 1501 \u2013 8 August 1524), was a Polish prince member of the House of Piast in the Masovian branch.", "He was a Duke of Czersk, Warsaw, Liw, Zakroczym and Nur during 1503-1524 (under regency until 1518) jointly with his brother.", "He was the eldest son of Konrad III the Red and his third wife Anna, a daughter of Mikolaj Radziwi\u0142\u0142 \"the Old\", Voivod of Vilnius and the first Grand Chancellor of Lithuania."]], ["Siemowit I of Masovia", ["Siemowit I of Masovia( c. 1224/28 \u2013 23 June 1262), was a Polish prince member of the House of Piast, Duke of Czersk during 1247- 1248, Duke of Masovia( except Dobrzy \u0144) during 1248- 1262, ruler over Sieradz during 1259- 1260.", "He was the sixth son of Konrad I of Masovia and his wife Agafia of Rus.", "He was named after his older brother Siemowit, who died young in 1224."]], ["Sophia of Masovia", ["Sophia of Masovia( 1497/1498- before 11 March 1543) was a Princess of Masovia, daughter of Konrad III Rudy, Duke of Masovia and his wife Anna Radziwi\u0142\u0142.", "She was a member of the House of Piast.", "On 17 September 1520 in Warsaw, Sophia was married by proxy to Stephen VII B\u00e1thory.", "On 17 January 1521, Sophia and her entourage went to Hungary, where in February there was a formal marriage.", "The couple had three children:", "Anna, Stephen and Klara; however, other sources claim that Klara was the couple's only child.", "Klara was engaged to Carl, Duke of M\u00fcnsterberg, but died in 1535, before the marriage took place.", "After the death of Stephen in 1530, Sophia was married to Croatian magnate Louis Pekry.", "Sophia's second marriage was childless.", "She then died sometime before 11 March 1543.", "Sophia had three siblings: Stanislaus I of Masovia, Janusz III of Masovia and Anna of Masovia, both her brothers died childless and so Anna and Sophia were the last Masovian Piasts.", "Soon after Janusz's death, the Duchy of Masovia was annexed into the kingdom of Poland, despite resistance from some of the Masovian nobility.", "They tried to retain their independence and argued that the Duchy should be inherited by the female relatives( such as Anna or Sophia).", "The Polish king refused to recognize their demands.", "Anna was made titular Duchess of Masovia."]], ["Anna of Masovia", ["Anna of Masovia( c. 1498 \u2013 after 26 January 1557 in Jaroslaw) was Princess of Mazovia and a member of the House of Piast.", "She was the last representative of the line of Masovian- Piast.", "She was the second daughter of Konrad III of Masovia and Anna Radziwi\u0142\u0142.", "She was a sister of Dukes Janusz III of Masovia and Stanislaus of Masovia, and Sophia, who married Stephen VII B\u00e1thory."]], ["Lyon Cohen", ["Lyon Cohen( 1868\u20131937) was a Polish- born Canadian businessman and a philanthropist.", "He was the grandfather of singer/ poet Leonard Cohen."]], ["Siemowit III, Duke of Masovia", ["Siemowit III of Masovia( his name also rendered Ziemowit; \u2013 1381) was a prince of Masovia and a co-regent( with his brother Casimir I of Warsaw) of the lands of Warsaw, Czersk, Rawa, Gostynin and other parts of Masovia."]], ["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."]], ["Gaudemunda of Lithuania", ["Gaudemunda Sophia of Lithuania( also Gaudimant\u0117; c. 1260 \u2013 1288/1313) was the daughter of Traidenis, Grand Duke of Lithuania( c. 1270 \u2013 1282).", "In 1279 she married Duke of Masovia Boles\u0142aw II( c. 1254\u20131313) of the Piast dynasty.", "He was the son of Ziemowit I, Prince of Masovia, and Pereyaslava, daughter of Daniel of Galicia of the Rurik dynasty.", "Her husband united the Duchy of Masovia and then divided it between their sons, who were:"]], ["Konrad III Rudy", ["Konrad III the Red", "(pl: \"", "Konrad III Rudy\"; 1447/48 \u2013 28 October 1503), was a Polish prince member of the House of Piast in the Masovian branch.", "He was a duke of Czersk, Liw, Warsaw, Nur, \u0141om\u017ca, Ciechan\u00f3w, R\u00f3\u017can, Zakroczym and Wyszogr\u00f3d during 1454-1471 jointly with his brothers (under regency until 1462), Duke of P\u0142ock, Wizna, P\u0142o\u0144sk and Zawkrze during 1462-1471, and after the division of the paternal domains in 1471, sole ruler over Czersk and Liw, over Wyszogr\u00f3d during 1474-1489 and again in 1495, over Zakroczym since 1484, over Nur since 1488 and over Warsaw since 1489.", "He was the third son of Boles\u0142aw IV of Warsaw and Barbara Olelkovna of Slutsk-Kapy, a Lithuanian princess, (granddaughter of Vladimir Olgerdovich).", "The premature death of his two older brothers during 1453-1454 left him as the eldest surviving son of his family."]]]
supporting_facts: [["Stanis\u0142aw of Masovia", 2], ["Konrad III Rudy", 4]]
evidences: [["Stanis\u0142aw of Masovia", "father", "Konrad III the Red"], ["Konrad III the Red", "father", "Boles\u0142aw IV of Warsaw"]]
answer: Bolesław IV of Warsaw