$$$
    Function
    Description
@@@
    Algorithm
@@@
    Usage
    Command line arguments
    Input file format
$$$ reads any normal sequence USAs.
    Output file format
    Data files
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    Notes
@@@ None.
    References
@@@ None.
    Warnings
@@@ None.
    Diagnostic Error Messages
@@@ None.
    Exit status
It always exits with status 0.
    Known bugs
None.
    Author(s)
    History
Written (date) - author.
    Target users