question: Who is Jan Of Cieszyn's paternal grandfather?
context: [["Elizabeth Lucretia, Duchess of Cieszyn", ["Elizabeth Lucretia of Cieszyn; 1 June 1599 \u2013 19 May 1653), was a reigning Duchess of Cieszyn( Teschen, T\u011b\u0161\u00edn) from 1625 until her death.", "Born as the third child and second daughter of Adam Wenceslaus, Duke of Cieszyn( by his wife Elisabeth, daughter of Gotthard Kettler, Duke of Courland), she was the last ruler of Cieszyn from the Polish Piast dynasty."]], ["Wenceslaus III Adam, Duke of Cieszyn", ["Wenceslaus III Adam of Cieszyn (December 1524 \u2013 4 November 1579) was a Duke of Cieszyn from 1528 until his death.", "He was the second but only surviving son of Wenceslaus II, co-Duke of Cieszyn, by his wife Anna, daughter of Frederick I, Margrave of Brandenburg-Ansbach.", "He was born one month after his father's death, on 17 November 1524."]], ["Hedwig of Cieszyn", ["Hedwig of Cieszyn( 1469 \u2013 6 April 1521) was a Polish princess.", "She was the only child of Przemys\u0142aw II, Duke of Cieszyn by his wife Anna, daughter of Duke Boles\u0142aw IV of Warsaw."]], ["Frederick William, Duke of Cieszyn", ["Frederick William of Cieszyn (9 November 1601 \u2013 19 August 1625) was a Duke of Cieszyn since 1617 until his death.", "He was the third but only surviving son of Adam Wenceslaus, Duke of Cieszyn, by his wife Elisabeth, daughter of Gotthard Kettler, Duke of Courland.", "His mother died from childbirth complications ten days after his birth, on 19 November 1602."]], ["Wenceslaus II, Duke of Cieszyn", ["Wenceslaus II of Cieszyn( b. 1488/96- d. 17 November 1524), was a Duke of Cieszyn since 1518 until his death( as co-ruler of his father).", "He was the second son of Casimir II, Duke of Cieszyn, by his wife Johanna, daughter of Wiktoryn of Pod\u011bbrady, Duke of Opawa."]], ["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."]], ["Frederick Casimir of Cieszyn", ["Frederick Casimir of Cieszyn also known as of Fry\u0161t\u00e1t (b. December 1541/January 1542 - d. 4 May 1571), was a Polish prince member of the House of Piast in the Cieszyn branch and ruler over Fry\u0161t\u00e1t, Skocz\u00f3w (both since 1560), and Bielsko (since 1565).", "He was the second child but only son of Wenceslaus III Adam, Duke of Cieszyn, by his first wife Maria, daughter of Jan of Pern\u0161tejn."]], ["Jan of Cieszyn", ["Jan of Cieszyn (1339/40 \u2013 after 18 May 1359), was a Polish prince, member of the Piast dynasty in the Cieszyn branch.", "He was the fourth son of Casimir I, Duke of Cieszyn, by his wife Euphemia, daughter of Duke Trojden", "I of Czersk-Warsaw."]], ["Johan Braakensiek", ["Johan Coenraad Braakensiek( 24 May 1858, Amsterdam \u2013 27 February 1940, Amsterdam) was a Dutch painter, illustrator and political cartoonist.", "He is the grandfather of Jan van Oort."]], ["Casimir I, Duke of Cieszyn", ["Casimir I of Cieszyn (1280/90 \u2013), was Duke of Cieszyn from 1315, Duke of Siewierz from 1337 and Duke of Bytom from 1357.", "He was the second son of Mieszko I, Duke of Cieszyn by his wife, probably called Grzymis\u0142awa."]]]
supporting_facts: [["Jan of Cieszyn", 1], ["Casimir I, Duke of Cieszyn", 1]]
evidences: [["Jan of Cieszyn", "father", "Casimir I, Duke of Cieszyn"], ["Casimir I, Duke of Cieszyn", "father", "Mieszko I, Duke of Cieszyn"]]
answer: Mieszko I, Duke of Cieszyn