Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE Documents_with_expenses (budget_type_code VARCHAR)
### Question:
What is the budget type code with most number of documents.
### Answer:
SELECT budget_type_code FROM Documents_with_expenses GROUP BY budget_type_code ORDER BY COUNT(*) DESC LIMIT 1