#!/usr/bin/perl -w

use strict;
binmode STDOUT, ":utf8";
use utf8;

use JSON;

my $json;
{
  local $/; #Enable 'slurp' mode
  open my $fh, "<", $ARGV[0];
  $json = <$fh>;
  close $fh;
}
# get it to a scalar
my $j = "[" . $json . "]";

my $decoded_json = decode_json( $j );

my $recommends_list = "";
for my $record ( @$decoded_json ) {
  foreach my $key ( keys(%$record) ) {
    $recommends_list = $recommends_list . $key . ", ";
  }
}
print $recommends_list;