use strict;
use warnings;

while (<DATA>){
  chomp;
  my @ele = split /\s/,$_;


##</code><code>##

use strict;
use warnings;

my %res;
while (<DATA>){
  chomp;
  my @ele = split /\s/,$_;

  push @{ $res{"$ele[1] $ele[2]"} }, $ele[0];
}
__DATA__
1 monkey cow hammer nail
2 monkey sheep hammer nail
3 dog cat hammer nail
4 monkey cow hammer nail


##</code><code>##

foreach my $key (keys %res){

  if ($key =~ /monkey/) {

     print "monkey [occurence in $key] found in IDs:", (join ', ', @{$res{$key}}), "\n";