Function a($,$c)

 dim $i,$j

 $= split($)
 $i = -1

 while $j<>9 | $i<>$c

  $i = ($i + 1) * ($i < ubound($))

  for $j = $[$i] to 8
   if ascan($,$j+1) > -1
    $j = 9
   endif
  next

  if $j = 9
   $[$i] = 0
   $a = $a + 1

EndFunction