$d=shift;for(1..$d){$c.=int(rand(10))}$t=$m=320;$|=1;while($d){$g='';for(1..$d){$g.=int(rand(10))}print"$w$g\r";if(substr($g,0,1)eq substr($c,0,1)){if($t){$t--;}else{$w.=substr($c,0,1,'');$d--;$t=$m;}}}