Task: Question Answering
Input (English): Context: Owain was married twice, first to Gwladus ferch Llywarch ap Trahaearn, by whom he had two sons, Maelgwn ab Owain Gwynedd and Iorwerth Drwyndwn, the father of Llywelyn the Great, then to Cristin, by whom he had three sons including Dafydd ab Owain Gwynedd and Rhodri ab Owain Gwynedd. 
 Question: Who is the offspring of Owain Gwynedd?
Output (English): iorwerth drwyndwn