>test_ambiguous_k33
ACGTACGTACGTACGTACGTACGTACGTACGACGTACGTACGTACGTACGTACGTACGNN
>test_ambiguous_k48
ACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGNNNNNNNN
>test_ambiguous_k64
ACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGTACGNNNNNNNNNNNNNNNNNNNNNNNN