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:When Purvis was released he was unable to even play a chord and he required some months of physical therapy at the Army Rehabilitation Center in Santa Barbara , California before he could resume his career . Sentence 2:nan
Example Output: SINGLE_S_COORD_ANAPHORA

Example Input: Sentence 1:After his death the show was again renamed Summer Nights and ran five more years . Sentence 2:nan
Example Output: SINGLE_VP_COORD

Example Input: Sentence 1:Emphasizing malware prevention , new features include SONAR , which looks for suspicious application behavior . Sentence 2:This release adds real - time exploit protection , preventing attackers from leveraging common browser and application vulnerabilities .
Example Output:
PAIR_NONE