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'.

Ex Input:
Sentence 1:Although most of his work went unpublished , Taylor was the first psychologist known to use exposure therapy treatment for anxiety , including methods of situational exposure with response prevention -- a common exposure therapy technique still being used . Sentence 2:nan

Ex Output:
SINGLE_CONN_START


Ex Input:
Sentence 1:Jump up ^ ITIS Report . Sentence 2:Copelatus , 112561 .

Ex Output:
PAIR_NONE


Ex Input:
Sentence 1:Bordering the Whanganui River , it incorporates areas of Crown land , former state forest and a number of former reserves . Sentence 2:nan

Ex Output:

SINGLE_CATAPHORA