Task: Question Answering
Input (English): William entered the staircase. Abigail entered the staircase. The watermelon is in the green_box. Abigail exited the staircase. William moved the watermelon to the green_treasure_chest. William exited the staircase. Abigail entered the staircase. Where was the watermelon at the beginning?
Output (English): green_box