In this task, you are given two sentences in the English language (Sentence 1 and Sentence 2). Your task is to identify the connecting word between the two sentences.

Example Input: Sentence 1:basically listening to Dinah Washington , Billie Holiday , and Frank Sinatra . Sentence 2:But also a lot of piano players , such as Bill Evans , Oscar Peterson and Erroll Garner , those were my mother 's favorites .
Example Output: but

Example Input: Sentence 1:This leads to a situation where the displacement through - the - thickness is not necessarily linear and where the plate thickness may change during deformation . Sentence 2:Therefore , Reissner 's theory does not invoke the plane stress condition .
Example Output: therefore

Example Input: Sentence 1:Therefore , the number of incident pairs is the sum of the degrees . Sentence 2:However , each edge in the graph belongs to exactly two incident pairs , one for each of its endpoints ; therefore , the number of incident pairs is 2
Example Output:
however