List instances with OS based on AMI Doesnt handle duplicates

#!/usr/bin/perl

use strict;
use warnings;

my $ImageId;
my $InstanceID;
my $Name;
my %Instances;
my %Names;

open (my $fh1, "aws ec2 describe-instances --query 'Reservations[*].Instances[*].[ImageId,InstanceId]' --output text |") or die $!;
while (<$fh1>) {
($ImageId,$InstanceID) = split;
$Instances{$ImageId} = $InstanceID;
}
close $fh1;

open (my $fh2, "aws ec2 describe-instances --query 'Reservations[*].Instances[*].ImageId' --output text | xargs aws ec2 describe-images --query 'Images[*].[ImageId,Name]' --output text --image-ids |") or die $!;
while (<$fh2>) {
($ImageId,$Name) = split;
$Names{$ImageId} = $Name;
}
close $fh2;

for my $Index (keys %Instances) {
        #print "$Index, $Instances{$Index}, $Names{$Index}\n";
        print "$Instances{$Index}, $Names{$Index}\n";
}