Task: Story Composition
Input (English): Premise: I made a sandwich today for lunch. 
 Initial Context: I put turkey and cheese on it. 
 Original Ending: Unfortunately, I ran all out of mayo. Even though I didn't have mayo, the sandwich was still tasty. Tonight I'll have to go buy some mayo. 
 Counterfactual Context: I put lots of mayonnaise on my sandwich.
Output (English): Unfortunately, I ran all out of cheese. Even though I didn't have cheese, the sandwich was still tasty. Tonight I'll have to go buy some cheese.