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:Strong , who had known Pico since 1867 , purchased the property and had it restored in 1909 . Sentence 2:nan

Ex Output:
SINGLE_RELATIVE


Ex Input:
Sentence 1:The format has grown to many other cities , including New York , Los Angeles , Denver , Miami , and Albuquerque , NM . Sentence 2:But more Recently , the format has been replaced in several cities .

Ex Output:
PAIR_CONN


Ex Input:
Sentence 1:If Chinlestegophis is indeed both an advanced stereospondyl and a relative of caecilians , this means that although all lissamphibians are descended from temnospondyls . Sentence 2:nan

Ex Output:

SINGLE_CONN_INNER