#!/usr/perl/bin/perl

use Modern::Perl;

$|=1;

my($data) = '/root/Desktop/inputfile.txt';

open STDIN, '<', $data 
    or die "File error: input file: $!";
open STDOUT, '>', '/root/Desktop/output.log' 
    or die "File error: output file: $!";

my(%result) = ();

while (defined($_ = <STDIN>)) {
    chomp $_;
    my ($index, $value) = split( /\s/, $_, 0 );
    $result{$index} = $value;
}
while (my ($index, $value) = each(%result)) {
    do {
        say "$index => $value" if $value > 500;
    };
} 
close STDIN;
close STDOUT;