Test your ability to memorize X random digits

#!/usr/bin/perl
#
# Usage: ./braintest.pl <# of digits>
#
#
# Change rand(10) to rand(2) to do binary
# sleep(15) allows 15 seconds to memorize obviously for longer strings much more time will be needed.
#


for($x = 0; $x < $ARGV[0]; $x++)
{
   $num = int(rand(10));
   $bin = $bin.$num;
}
   print "$bin\n";
sleep(15);
for($x = 0; $x < 1000; $x++){print "\n"; }

print "Enter number: ";
$test = <STDIN>;
chomp($test);

if($test == $bin) { print "Correct!\n"; }
else { print "Wrong $bin\n";}