#!/usr/bin/perl -w
use strict;

my @whole_file = <>;
my @new_array = sort by_first_field @whole_file;
print @new_array;

sub by_first_field {
  $a =~ /^(.*?) ,/;
  my $x = $1;
  $b =~ /^(.*?) ,/;
  my $y = $1;
  return $x <=> $y;
}