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:In 2000 , Meijin - 2000 played against human players in Moscow Open Tournament . Sentence 2:However , not until 2017 were the computer programs proved to be able to outperform top human players in public competitions .
however