Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The chief executive of Renault-Nissan has told the BBC he is "reasonably optimistic" that the UK will be an important partner with the European Union, despite its vote to leave.

Renault-Nissan 'reasonably optimistic' over Brexit