Given the task definition and input, reply with output. 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.

Sentence 1:Studies have found that collaboration can increase achievement and productivity . Sentence 2:However , a four - year study of interorganizational collaboration found that successful collaboration can be rapidly derailed through external policy steering , particularly where it undermines relations built on trust .
however