Batch Apex to count the processed records

Public class countProcessed implements Database.Batchable<Sobject>,Database.Stateful{

    Public integer count = 0;

    

    Public Database.QueryLocator start(Database.BatchableContext bc){

        String str ='select id,Name,Rating from Account';

        return Database.getQueryLocator (str);

    }

    

    Public void execute(Database.BatchableContext bc, List<Account> lAcc){

        for(Account a :lAcc){

            a.Rating = 'Cold'; 

        }

        

        try{

            Database.SaveResult[] s =  Database.update(lAcc,false);

            for(database.SaveResult d : s){

                if(d.isSuccess()){

                    count++;

                }

                

            }

        }

        catch(exception e){

            system.debug('failed');

        }

    }

    

    Public void Finish(Database.BatchableContext bc){

        system.debug(count);

        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();

        String[] toAddresses = new String[] {'archanaonline91@gmail.com'};

            mail.setToAddresses(toAddresses);

        mail.setSubject('Done');

        mail.setPlainTextBody(count +'  '+ 'records have been updated sucessfully');

        Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });

    }

}

Execution batch job from Developer Console: 

countProcessed cp = new countProcessed();

Database.executeBatch(cp);

To check the result -