Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: FreeBSD is a free Unix-like operating system descended from Research Unix via the Berkeley Software Distribution (BSD). 
 Question: The FreeBSD is based upon what?
Example Output: berkeley software distribution

Example Input: Context: The Sakya see was ruled in this period by Zangpo Pal (1306-1323); one of his many sons, Kunga Lotro Gyaltsen, succeeded Sanggye Pal at his demise in 1314. 
 Question: Which replaced the Sanggye Pal?
Example Output: kunga lotro gyaltsen

Example Input: Context: Sir Wilfred Robarts, a famed barrister, has just been released from the hospital in which he stayed for two months following a heart attack. Returning to his practise of law, he takes the case of Leonard Vole, an unemployed man who is accused of murdering his elderly friend, Mrs. Emily French. Vole claims he's innocent, although all evidence points to him as the killer, but his alibi witness, his cold German wife Christine, instead of entering the court as a witness for the defense, becomes the witness for the prosecution and defiantly testifies that her husband is guilty of the murder. Sir Wilfred believes there's something suspicious going on with the case, particularly with Mrs. Vole. 
 Question: Who stabs Leonard?
Example Output:
christine