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.

Ex Input:
Sentence 1:As an example , it is physically possible to make interchangeable screws , bolts , and nuts entirely with freehand toolpaths . Sentence 2:But it is economically practical to make them only with machine tools .

Ex Output:
but


Ex Input:
Sentence 1:The fall would have been 16 metres ( 52 ft ) , astonishing in 1749 . Sentence 2:However the approach tunnel proved to be unusable in times of flood and the shaft lock was replaced by a 2 - rise staircase in 1768 .

Ex Output:
however


Ex Input:
Sentence 1:Because of the variable internal sequence , the motif can not be detected . Sentence 2:However , if we could use a program to search for motifs containing a variable sequence in the middle , without counting mutations , these motifs could be discovered .

Ex Output:

however