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:Carriers of the gene , who are healthy and normal , can be identified by a DNA test . Sentence 2:nan
Example Output: SINGLE_RELATIVE

Example Input: Sentence 1:As they prepare for Thanksgiving , Jeffrey struggles to teach Hugh how to make the perfect pie and John makes plans to hunt for his turkey dinner . Sentence 2:Meanwhile , John finds out about Stella 's relationship with the doctor hired to replace him .
Example Output: PAIR_CONN_ANAPHORA

Example Input: Sentence 1:Regional Dialogues : With the aim of widening the scope and outreach of the WSDS , a series of pre-events in the form of Regional Dialogues are held throughout the country , prior to the Summit . Sentence 2:nan
Example Output:
SINGLE_APPOSITION