use strict;
# use Stream;
use Math::Pari qw(gcd);
 
# We can test all the factors at once using the greatest common divisor algorithm.
my @factors = @ARGV;
my $test_number = 1;
$test_number *= $_ for @factors;
die "Must provide a list of non-zero factors\n" unless $test_number > 1;
 
sub has_common_factor { gcd($_[0], $test_number) != 1 }
 
# my $integers = Stream::tabulate( sub { $_[0] }, 1);
# my $challenge = $integers->filter(\&has_common_factor);
# $challenge->show(50);

print "@{[grep has_common_factor($_), 1..50]}\n";

##</code><code>##

sub tail {
  my $t = $_[0]{t};
  if (ref $t eq CODE) {		# It is a promise
    $_[0]{t} = &$t;  # <--- there!
  }
  $_[0]{t};
}

##</code><code>##

 R:  number of primes in the input
c1:  number of times merge was called
c2:  number of times a < comparison was executed in merge
c3:  time factor predicted by formula
r1:  c1/c3
r2:  c2/c3

R    c1    c2    c3   r1    r2
 2  2002  3002  1667 1.201 1.801
 3  3276  5095  4133 0.793 1.233
 4  4227  6821  7057 0.599 0.967
 5  4989  8203 10137 0.492 0.809
 6  5673  9534 13440 0.422 0.709
 7  6303 10744 16834 0.374 0.638
 8  6921 11966 20377 0.340 0.587
 9  7499 13098 23983 0.313 0.546
10  8015 14108 27602 0.290 0.511
11  8538 15149 31314 0.273 0.484
12  9025 16107 35040 0.258 0.460