#!/usr/bin/perl -w eval 'exec /usr/bin/perl -S $0 ${1+"$@"}' if 0; use strict; (my $ME = $0) =~ s|.*/||; # A global destructor to close standard output with error checking. sub END { defined fileno STDOUT or return; close STDOUT and return; warn "$ME: closing standard output: $!\n"; $? ||= 1; } sub is_prime ($) { my ($n) = @_; use integer; $n == 2 and return 1; my $d = 2; my $w = 1; while (1) { my $q = $n / $d; $n == $q * $d and return 0; $d += $w; $q < $d and last; $w = 2; } return 1; } { @ARGV == 1 or die "$ME: missing argument\n"; my $wheel_size = $ARGV[0]; my @primes = (2); my $product = $primes[0]; my $n_primes = 1; for (my $i = 3; ; $i += 2) { if (is_prime $i) { push @primes, $i; $product *= $i; ++$n_primes == $wheel_size and last; } } my $ws_m1 = $wheel_size - 1; print <