WITH coins AS (
  SELECT 1 cents FROM DUAL
  UNION ALL SELECT 5 cents FROM DUAL
  UNION ALL SELECT 10 cents FROM DUAL
  UNION ALL SELECT 25 cents FROM DUAL
  UNION ALL SELECT 50 cents FROM DUAL
  )
,t(c1,c5,c10,c25,c50,cents,total_val) AS (
SELECT DECODE(c.cents,1,1,0)
      ,DECODE(c.cents,5,1,0)
      ,DECODE(c.cents,10,1,0)
      ,DECODE(c.cents,25,1,0)
      ,DECODE(c.cents,50,1,0)
      ,cents
      ,cents
  FROM coins c
UNION ALL
SELECT c1 + DECODE(c.cents,1,1,0)
      ,c5 + DECODE(c.cents,5,1,0)
      ,c10+ DECODE(c.cents,10,1,0)
      ,c25+ DECODE(c.cents,25,1,0)
      ,c50+ DECODE(c.cents,50,1,0)
      ,c.cents
      ,t.total_val + c.cents
  FROM t, coins c
WHERE t.total_val + c.cents<=100 AND t.cents<=c.cents
)
,t2 AS (
SELECT DISTINCT c1+c5+c10+c25+c50 cnt FROM t WHERE total_val=100
)
SELECT MIN(rn)
 FROM (SELECT ROWNUM+1 rn FROM DUAL CONNECT BY ROWNUM<100
       )
WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE cnt=rn);