for(integer i=0; i < allAccts.size(); i++){
             if (allAccts.get(i).Rating__c == 'Do Not Use' ) {
                 masterRec = allAccts.get(i);
                 allAccts.remove(i);

            List<Id> dupes = new List<Id>();
            for(Account b : allAccts){
                 if (masterRec.Number__c == b.Number__c && masterRec.Id != b.Id) {

                     dupes.add(b.Id);

                 }
                 mapRaccts.put(masterRec.Number__c, dupes );