...
 use String::LCSS_XS qw(lcss);
  
 my $str_a =  join '', map sprintf("%08x", $_), 1,2,3,6,7,9,1,-7,2,6;
 my $str_b =  join '', map sprintf("%08x", $_), 7,6,7,9,12,-22,-3;

 # - - - - - - - - - - - - - - - - - - - #
 my @longest = lcss( $str_a, $str_b );
 # - - - - - - - - - - - - - - - - - - - #
 print join ',', map hex, $longest[0] =~ /.{8}/g;

 my ($pa, $pb) = map 1+$_/8, @longest[1,2];
 print "\na's pos # $pa alingns to b's pos # $pb\n";
 ...

##</code><code>##

 6,7,9
 a's pos # 4 'aligns' to b's pos # 2