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'.

Example Input: Sentence 1:A special cloud falls out of the sky and lands on Tinky Winky 's head . Sentence 2:Tinky Winky shows his special cloud to the others and they all think it is beautiful .
Example Output: PAIR_ANAPHORA

Example Input: Sentence 1:The Aztec canoe fleets worked well for attacking the Spanish because they allowed the Aztecs to surround the Spanish on both sides of the causeway . Sentence 2:nan
Example Output: SINGLE_CONN_INNER_ANAPHORA

Example Input: Sentence 1:Alison Davis - Blake , the former dean of the Carlson School of Management at the University of Minnesota and of the Ross School of Business at the University of Michigan , became Bentley 's eighth president in July 2018 . Sentence 2:nan
Example Output:
SINGLE_APPOSITION