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:Ambulocetus was the size of a male sea lion , much larger than Pakicetus . Sentence 2:Thewissen et al. estimated the body weight of Ambulocetus at 141 -- 235 kg ( 311 -- 518 lb ) , while Philip D. Gingerich estimated it at 720 kg ( 1,590 lb ) .

Ex Output:
PAIR_ANAPHORA


Ex Input:
Sentence 1:This includes sole credit on an episode of Palmerstown USA ( 1980 ) , a CBS series by Alex Haley and Norman Lear , as well as work on The Lazarus Syndrome ( 1978 ) and Freedom Road ( 1979 ) . Sentence 2:nan

Ex Output:
SINGLE_APPOSITION


Ex Input:
Sentence 1:George seemingly retired after his last game in Washington , but he proceeded to make several sideline appearances in the following years . Sentence 2:nan

Ex Output:

SINGLE_S_COORD_ANAPHORA