#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

use Data::Dump;

my @files = qw{
    pm_1227048_raw_1
    pm_1227048_raw_2
    pm_1227048_raw_3
};
my %trio;

for my $file (@files) {
    open my $fh, '<', $file;

    while (<$fh>) {
        chomp;
        my ($k, $v) = split / => /;
        push @{$trio{$k}}, $v;
    }
}

# This step for demonstration purposes only
print "All data:\n";
dd \%trio;

# Extra step due to poor input
print "Data with 2 or more values:\n";
delete @trio{grep @{$trio{$_}} < 2, keys %trio};
dd \%trio;

# Only this step required with better input
print "Data with 3 or more values:\n";
delete @trio{grep @{$trio{$_}} < 3, keys %trio};
dd \%trio;