Select Code to Download

use strict;
use List::Util qw(reduce);
...
          $index++;
          $b;
       } @data;

match 81 starting at index 6
match 82 starting at index 22

for my $i (0 .. $#data) {
    if ( $data[$i] eq $data[$i+1] && $data[$i] =~ m/81|82/) {
        print "match $data[$i] starting at index $i\n";
    }
}