my $dna = q(accatgagctgtacgtagcatctgagcgcgcatgactgtgactgacgtaggcagca);
my $skip = 10;
{
    local ($/, $\) = (\10, "\n");
    open my $chain, '<', \substr($dna, $skip) or die $!;
    print while <$chain>;
    close $chain or die $!;
}