RosettaCodeData/Task/Digital-root-Multiplicative-digital-root/Zkl/digital-root-multiplicative-digital-root-1.zkl

fcn mdroot(n){ // Multiplicative digital root
   mdr := List(n);
   while (mdr[-1] > 9){
      mdr.append(mdr[-1].split().reduce('*,1));
   }
   return(mdr.len() - 1, mdr[-1]);
}