You will be given a definition of a task first, then some input of the task.
You are given two sentences(Sentence1 and Sentence2). Answer "Yes" if these sentences are a paraphrase of one another, otherwise answer "No".

Sentence1: Harris and Klebold killed 12 students and a teacher before taking their own lives on April 20 , 1999 ., Sentence2: Harris and Klebold killed 12 students , a teacher and themselves at the school .
Output:
Yes