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:St. Athanasius is often quoted as endorsing 39 books in his Old Testament , rejecting any apocryphal ( pseudepigraphal ) writings . Sentence 2:However , his 39 books are different from the Protestant canon in that he rejects Esther and includes Baruch .
Example Output: PAIR_CONN_ANAPHORA

Example Input: Sentence 1:After the Castle was completed , Charles became Ambassador to Russia in 1841 . Sentence 2:However ill - health caused his return to England and he died at Highcliffe in 1845 .
Example Output: PAIR_CONN_ANAPHORA

Example Input: Sentence 1:Que'er , a quirky bird demon , rescues Xiaowei , and the two leave in search of a man who is willing to give his heart to Xiaowei so that she may become human . Sentence 2:nan
Example Output:
SINGLE_CONN_INNER_ANAPHORA