my $dna = join '', lines q:to/END/;
    CGTAAAAAATTACAACGTCCTTTGGCTATCTCTTAAACTCCTGCTAAATG
    CTCGTGCTTTCCAATTATGTAAGCGTTCCGAGACGGGGTGGTCGATTCTG
    AGGACAAAGGTCAAGATGGAGCGCATCGAACGCAATAAGGATCATTTGAT
    GGGACGTTTCGTCGACAAAGTCTTGTTTCGAGAGTAACGGCTACCGTCTT
    CGATTCTGCTTATAACACTATGTTCTTATGAAATGGATGTTCTGAGTTGG
    TCAGTCCCAATGTGCGGGGTTTCTTTTAGTACGTCGGGAGTGGTATTATA
    TTTAATTTTTCTATATAGCGATCTGTATTTAAGCAATTCATTTAGGTTAT
    CGCCGCGATGCTCGGTTCGGACCGCCAAGCATCTGGCTCCACTGCTAGTG
    TCCTAAATTTGAATGGCAAACACAAATAAGATTTAGCAATTCGTGTAGAC
    GACCGGGGACTTGCATGATGGGAGCAGCTTTGTTAAACTACGAACGTAAT
    END


put pretty($dna, 80);
put "\nTotal bases: ", +my $bases = $dna.comb.Bag;
put $bases.sort(~*.key).join: "\n";

sub pretty ($string, $wrap = 50) {
    $string.comb($wrap).map( { sprintf "%8d: %s", $++ * $wrap, $_ } ).join: "\n"
}