import re


def parse_final_answer(text, num_docs):
    patterns = [
        rf"【最终答案】\s*([0-3]{{{num_docs}}})",
        rf"最终答案\s*[:：]?\s*([0-3]{{{num_docs}}})",
        rf"答案\s*[:：]?\s*([0-3]{{{num_docs}}})",
    ]
    for pattern in patterns:
        matches = re.findall(pattern, text, re.DOTALL)
        if matches:
            return matches[-1]
    matches = re.findall(rf"[0-3]{{{num_docs}}}", text)
    if matches:
        return matches[-1]
    return None