my @c;
        for (my $i = 0; $i < length; $i++) {
            for (my $j = 2; $i + $j <= length; $j++) {
                push @c, substr $_, $i, $j;
            }
        }

##</code><code>##

Attempt to free unreferenced scalar: SV 0x9730848, Perl interpreter: 0x970a008 at /tmp/perm2 line 17, <DATA> line 1.