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:There is also evidence which suggests the function of dystroglycan as a part of the signal transduction pathway because it is shown that Grb2 , a mediator of the Ras - related signal pathway , can interact with the cytoplasmic domain of dystroglycan . Sentence 2:nan
Example Output: SINGLE_APPOSITION

Example Input: Sentence 1:Regal targeted Finlay 's injured knee and attacked it . Sentence 2:However , Finlay protected his knee and tried to battle Regal but Regal continued to attack it and injured Finlay 's head .
Example Output: PAIR_CONN_ANAPHORA

Example Input: Sentence 1:Edy then travels to his store , a small neighborhood supermarket , called Bodega . Sentence 2:nan
Example Output:
SINGLE_APPOSITION