WITH sub AS (
  SELECT CLASS_CODE,
    CLASS_NAME,
    PERSON_NAME,
    SUM(AMT) AS sum_amt,
    ROW_NUMBER() OVER (
      PARTITION BY CLASS_CODE
      ORDER BY SUM(AMT) DESC
    ) AS row_num
  FROM HOUSEHOLD
  WHERE PERSON_CODE != 1
    AND CLASS_CODE != '01'
  GROUP BY CLASS_CODE,
    PERSON_CODE
)
SELECT CLASS_NAME AS CLASS,
  PERSON_NAME AS PERSON,
  sum_amt AS HOUSEHOLDS
FROM sub
WHERE row_num = 1
ORDER BY CLASS_CODE;