Here is a set of basic questions producing integer or string outputs. Answer them and format the result precisely with the JSON instructions provided:

Question 0 (Question id: q_hCOikOd):
Determine the value of a that satisfies: 15 - 4*a = -21 Respond with an integer.

Question 1 (Question id: q_9uqY):
How many times does the letter "a" appear in the text: "United Kingdom falls"? Respond with an integer.

Question 2 (Question id: q_VHNpA0):
Find the value of l in the equation: l + 6 = 19 Respond with an integer.



Your output must be a JSON mapping every question id to its answer info.

The value for each key should be an object that contains the answer in the field 'answer'.
Include an 'answer_type' field (value 'string' or 'integer') for every answer object.
For even integer answers, include 'half_answer' equal to answer ÷ 2.
For string answers, include 'first_char' with the answer’s initial letter.
If the question asks for the last character of a string, add an 'original_string' field containing the source string.

Now provide the result JSON using the described format.

{"ground_truth": {"q_hCOikOd": {"answer": 9, "answer_type": "integer"}, "q_9uqY": {"answer": 1, "answer_type": "integer"}, "q_VHNpA0": {"answer": 13, "answer_type": "integer"}}}