use strict;
use warnings;
use Tie::File;

my $first   = shift || die "first file\n";
my $sec     = shift || die "second\n";

tie my @first,'Tie::File',$first or die "tie error $!\n";
tie my @sec  ,'Tie::File',$sec or die "tie error $!\n";

my (%h1,%h2,%common);

print "processing $first\n";
map {
  if(/^\s*(\?.*?)\s/) {
    $h1{$1}++;
  }
} @first;

print "processing $sec\n";
map {
  if(/^\s*(\?.*?)\s/) {
    $h2{$1}++;
  }
} @sec;

print "finding common keys\n";
map {
  if(exists $h2{$_}) {
    $common{$_}++;
  }
} keys %h1;

print "there are @{[length keys %common]}:\n";
system("pause");
for my $key(keys %common) {
    print "\n\n\n$key\n\n\n";
}

untie @first;
untie @sec;