Task: Text to Code
Input (English): Step 1: For each row in Documents table, find the corresponding rows in Document_Sections table.
Step 2: find the number of rows of each value of document_name in the results of step 1.
Step 3: find section_title of step 1 results with smallest value in the results of step 2
Output (English): SELECT T2.section_title FROM Documents AS T1 JOIN Document_Sections AS T2 ON T1.document_code = T2.document_code GROUP BY T1.document_name ORDER BY Count ( * ) Asc LIMIT 1