Hi Folks, I have a use case that I need to display total  amount sum from opportunities object in finsh method... please help me ...

global class batchclass1 implements Database.Batchable<Opportunities>{
    
    global batchclass1(){}
        /* Batch class constructor */
    //Start method
    global Database.QueryLocator start(Database.BatchableContext BC)
    {
        String query='SELECT id, Amount from Opportunities';
         return Database.getQueryLocator(query);
        }

    //Excute method
    
global void execute(Database.BatchableContext BC, List<Opportunities> scope)
{
    //Excution logic
    List<Opportunities> opp= new List<Opportunities>
    AggregateResult[] gr= [SELECT SUM(Amount) FROM Opportunities];

    
}
      global void finish(Database.BatchableContext BC){
            // Finish logic
           system.debug('gr');
       }
    
    

}