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'.

Ex Input:
Sentence 1:Robert M. Ricketts developed the Utility arch in 1950s and it is considered to be an integral part of the Bioprogressive Therapy in Orthodontics . Sentence 2:nan

Ex Output:
SINGLE_S_COORD_ANAPHORA


Ex Input:
Sentence 1:Nothing Sado does is pleasing to the king , who proceeds to humiliate his son . Sentence 2:However , the Royal Queen Dowager is overjoyed at Sado 's wisdom and acts as his protector .

Ex Output:
PAIR_CONN_ANAPHORA


Ex Input:
Sentence 1:Actress Kajal Agarwal was approached to play the character which Nithya Menen originally played . Sentence 2:However , the director roped in actress Amulya , who successfully paired with Ganesh in Cheluvina Chittara and Shravani Subramanya , as the final lead actress .

Ex Output:

PAIR_CONN