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: Cologne mayor Henriette Reker, who survived a serious knife attack in 2015, has received a death threat just days after another German politician was shot dead, police say.

German pro-immigration mayors get death threats