#!perl
use strict;
use warnings;

my $infile  = $ARGV[0];
my $outfile = $ARGV[1];

open IN,'<',$infile or die "Could not open $infile : $!";
my %count  = ();
my @lines  = ();
while (<IN>){
  push @lines,$_;
  if (/^(\S+)/){
    ++$count{$1};
  }
}
close IN;

open OUT,'>',$outfile or die "Could not open $outfile : $!";
for (@lines){
  if (/^(\S+)/){
    print OUT $_ if $count{$1} > 1;
  }
}
close OUT;
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