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'.

Input: Consider Input: Sentence 1:The route availability code is RA8 , but freight trains above a certain size must not pass each other on the bridge . Sentence 2:nan

Output: SINGLE_S_COORD


Input: Consider Input: Sentence 1:The first thematic group is striking for the breadth of its melodic content , which is not usual for any symphony , and is not found in Enescu 's previous four essays in the form . Sentence 2:nan

Output: SINGLE_RELATIVE


Input: Consider Input: Sentence 1:A short section above the fourth lock remains in water , although the top gate of the lock has been replaced by a concrete wall Sentence 2:nan


Output: SINGLE_CONN_INNER