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:Witnesses later said they had seen police batoning a figure in the doorway where McCloskey was found , although police claimed that he had been unconscious before the baton charge and may have been hit with a stone . Sentence 2:nan
Example Output: SINGLE_CONN_INNER

Example Input: Sentence 1:The accuracy of the drawings in that work ( actually , two works , by father and son ) leaves much to be desired . Sentence 2:For example , the corridor containing Barbatus ' coffin is shown complete , when it has always ended in the rock ledge .
Example Output: PAIR_CONN

Example Input: Sentence 1:They have very little offensive capability but they have sharp teeth that can bite through steel cable and inflict nasty wounds . Sentence 2:nan
Example Output:
SINGLE_S_COORD