In this task, you are given two sentences in the English language and your task is to classify them into one of their discourse types. A discourse type is an indicator to classify the given two sentences on the basis of a co-text as well as a relevant context. There are 13 discourse types in total which are 'SINGLE_S_COORD', 'SINGLE_CATAPHORA', 'SINGLE_CONN_INNER', 'SINGLE_APPOSITION', 'SINGLE_VP_COORD', 'SINGLE_CONN_START', 'PAIR_ANAPHORA', 'PAIR_CONN', 'SINGLE_RELATIVE', 'SINGLE_CONN_INNER_ANAPHORA', 'SINGLE_S_COORD_ANAPHORA', 'PAIR_CONN_ANAPHORA' and 'PAIR_NONE'.

[Q]: Sentence 1:Descriptions of registered cultivars . Sentence 2:Retrieved 2006 - 11 - 15 .
[A]: PAIR_NONE


[Q]: Sentence 1:Adam had served as a royal chancellor in 1166 -- 67 and was the prior of the cathedral in Ourense at the time of his elevation . Sentence 2:nan
[A]: SINGLE_S_COORD_ANAPHORA


[Q]: Sentence 1:Surviving to become the most abundant baleen whale in the world , it is now one of the mainstays of the industry alongside its cosmopolitan counterpart the common minke . Sentence 2:nan
[A]:
SINGLE_CATAPHORA


