try:
    from langchain_community.chains import RetrievalQA
    print('from langchain_community.chains import RetrievalQA')
except Exception as e:
    print(f'community failed: {e}')

try:
    from langchain.chains import RetrievalQA
    print('from langchain.chains import RetrievalQA')
except Exception as e:
    print(f'langchain failed: {e}')

try:
    from langchain_classic.chains import RetrievalQA
    print('from langchain_classic.chains import RetrievalQA')
except Exception as e:
    print(f'classic failed: {e}')