Try this as a Custom Test Case:
21
9781118336922
0880221577
0070667608
9781305109919
9781305273764
201183991
0023609516
9783319175744
9783319515168
8131760529
812X335961
0672301997
ignore_meX
0830645918
0140088911
9780471142737
080442957X
097522980X
9781482587630
9781406891065
1544777434
Expected output:
3 invalid:
201183991
812X335961
ignore_meX