Among the accounts who have loan validity more than 24 months, list out the accounts that have the lowest approved amount and have account opening date before 1997.
SELECT T1.account_id FROM loan AS T1 INNER JOIN account AS T2 ON T1.account_id = T2.account_id WHERE T1.duration > 24 AND STRFTIME('%Y', T2.date) < '1997' ORDER BY T1.amount ASC LIMIT 1