Task: Story Composition
Input (English): Premise: My dog has gained some extra weight. 
 Initial Context: I've been trying to take him for a walk every day. 
 Original Ending: He's too small to walk for long. I end up having to carry him home. At least I'll lose some weight. 
 Counterfactual Context: I've been putting him on the treadmill every day.
Output (English): He's too small to walk for long. I end up having to stop the walk prematurely. I don't even get exercise myself.