Fix Off By One

The model receives the prompt (and optional system message). The run uses scorer contains_all with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Fix the bug and return corrected Python code only.

def first_three(nums):
    return nums[0:2]

{
  "expected_contains": [
    "def first_three(nums):",
    "nums[0:3]"
  ]
}