Task: Discourse Connective Identification
Input (English): Sentence 1:Anand , the tournament 's hitherto - untroubled No. 1 seed , breezed through the quarterfinal round against his longtime rival Vassily Ivanchuk . Sentence 2:But Boris Gelfand gave Anand a challenge in the semi-final , and the match was not settled until a sudden - death blitz game .
Output (English): but