do{srand($_);print((' ',a..z)[int(rand(27))])for 0..3}
for('185103579996010520472053207918834193'=~/(.{6})/g)

##</code><code>##

$x=join$",map{srand$_;join"",map{10+int rand 27}(1..4)}(0..10**6);print map{sprintf
"%06d",1/9*index$x,join"",map{10+ord()%32}/./g}"good job and unique idea"=~/.{4}/g