Definition: In this task, you will be given a short story. One sentence from the story is chosen. Consider the events that happen before that sentence, or are likely to have happened before it. Does any of them directly cause it, or simply make it possible? You should write your answer in the form " A >causes/enables> B". Try to use phrases and sentences from the story to compose your answer when possible.
Input: story: Kim bought her nephew a silly string toy as a gift. The whole family laughed as he chased his brother around the house. Kim's sister was upset there was silly string all over the walls. As Kim cleaned the string she found it stained walls with flat paint. Her sister yelled for an hour when she found out.
 selected sentence: As Kim cleaned the string she found it stained walls with flat paint.

Kim's sister is upset about the silly string on the walls >Causes/Enables> Kim cleans the string