#!/usr/bin/perl
    use strict;
    use warnings;
     
    use Data::Dumper qw(Dumper);

	my $line = <DATA>;
	my %hash;
		while($line){
			my ($tag1, $tag2, $tag3) = split(/\t/, $line);
				if ($tag2 =~/NN/) {
					$hash{$tag3}{frequency} = (($hash{$tag3}{frequency})+1);
					$hash{$tag3}{variants} = $tag1;
				} 
		$line = <DATA>;
		}
	
     
    print Dumper \%hash;

__DATA__
The	DT	the
International	NN	International
for	IN	for
well	NN	well
preparation	NN	preparation
preparation	NN	preparation
in	IN	in
conference	NN	conference
conference	NN	conference
conferences	NN	conference
good	VVG	good