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:The decrees of general councils need not be confirmed by the pope nor can they be altered by him ; on the other hand , appeal may be made from papal decisions to a general council . Sentence 2:nan
Example Output: SINGLE_S_COORD_ANAPHORA

Example Input: 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
Example Output: SINGLE_RELATIVE

Example Input: Sentence 1:The ship ran aground at the mouth of the River Burry . Sentence 2:She was on a voyage from Terceira Island , Azores to London .
Example Output:
PAIR_NONE