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:Milan then fell under the lordship of Sforza , whom Colleoni served for a time , but in 1448 he took leave of Sforza and returned to the Venetians . Sentence 2:nan
[A]: SINGLE_RELATIVE


[Q]: 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 .
[A]: PAIR_CONN


[Q]: Sentence 1:He called Abe ' Snowball ' but never seemed able , even with his best attempts , to upset him . Sentence 2:Muswell however eventually developed a grudging respect for the man .
[A]:
PAIR_CONN