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:Brian had two sisters : Pamela , who was born on 3 October 1943 and died on 14 October 1945 of leukemia ; and Barbara , born on 22 August 1946 . Sentence 2:nan
Example Output: SINGLE_RELATIVE

Example Input: Sentence 1:Foo.secondlifeherald.com. 2010 - 02 - 04 . Sentence 2:Retrieved 2013 - 12 - 14 .
Example Output: PAIR_NONE

Example Input: Sentence 1:Although Iotapa was annexed along with the Kingdom of Commagene by Roman Emperor Vespasian in 72 , Iotapa became a central city where coins were minted . Sentence 2:nan
Example Output:
SINGLE_CONN_START