use strict;

my %numb;
my @numb = (0..9);

for (0..9999) {
   my $numb;
   $numb .= $numb[rand @numb] for 0..5;
   $numb{$numb}++;
}

my @unique;

for (keys %numb) {
   push @unique,$_ if $numb{$_} == 1;
}

print scalar @unique, " unique values\n";