List<AggregateResult> acc=[SELECT Name  , Prospect_Code__c  , COUNT(Id) ids FROM Account where Id Not In (Select AccountId from Contact) And Id Not In (Select AccountId from Opportunity) GROUP BY Name, Prospect_Code__c  HAVING count(Id)>1];

Map<String,boolean> act = new Map<String,boolean>();

for(AggregateResult aggres : acc)

{

    act.put('duplicate__c',true);

    System.debug('Finding duplicate AccName,ProspCode with no relation with Contact and Opp'+aggres);

}