use strict;
use warnings;

use Regexp::Assemble;
my $id_regex = Regexp::Assemble->new;

my $IDFILE  = ...; # Your filenames here

open my $ifh, '<', $IDFILE or die "Could not open $IDFILE: $!";

while ( my $line = <$ifh> ) {
  $id_regex->add( substr $line, 0, 6 );
}

close $ifh;

open my $afh, '<', $AMPFILE or die "Could not open $AMPFILE: $!";
open my $ofh, '>', $OUTFILE or die "Could not open $OUTFILE: $!";

while ( my $line = <$afh> ) {
  chomp $line;
  if ( $line =~ $id_regex ) {
    my $next = <$afh>;
    print $ofh $line, "\t", $next if $next =~ /^Amp-commit/;
  }
}

close $ofh;
close $afh;