Teacher:In this task, you're given a sentence and your task is to generate a simplified sentence that focuses on lexical paraphrasing from the original sentence given in the input.
Teacher: Now, understand the problem? Solve this instance: west berlin had its own postal administration , separate from west germany 's , which issued its own postage stamps until 1990.
Student:
west berlin had its own postal administration , separate from west germany which issued its own postage stamps.