use prime;
use strict;


my @prime = prime::make_prime_table(100 * 10000);
my %prime_hash;
my $sum = 0;
my @lp;
my @rp;


foreach my $p (@prime) {
	$prime_hash{$p} = 1;
}

foreach my $p (@prime) {
	if ($p > 10 
		&&is_rprime($p) && is_lprime($p)) 
	{
		$sum += $p;
		print "$p\n";
	}
}

print "S:", $sum,"\n";

sub is_rprime
{
	my $n = shift;
	my $k = int(log($n) / log(10)) + 1;
	my $ok = 1;
	
	for (my $i = 1; $i <= $k; ++$i) {
		my $r = $n % (10 ** $i);
		if (!exists($prime_hash{$r})) {
			$ok = 0;
			last;
		}
	}
	
	return $ok;
}

sub is_lprime
{
	my $n = shift;
	my $k = int(log($n) / log(10)) + 1;
	my $ok = 1;
	
	for (my $i = 0; $i < $k; ++$i) {
		my $r = int($n / (10 ** $i));
		if (!exists($prime_hash{$r})) {
			$ok = 0;
			last;
		}
	}
	
	return $ok;
}