The test is 2 27
    I found that some AC solution output like that:
    a-z
    {-az
    ba-bz

    It means that the testdatas do not strong enough.
    Please add this.
    By the way,I guess the test 10 may be have some characters that do not in ['a'..'z','-']
    Please check it.
    At last,sorry for my poor English.
    Thank you.

    Test 10 is correct.I'm sorry.