global void execute(Database.BatchableContext bc, List<Account> accounts){
    List<Account> acctsToUpdate = new List<Account>();
    List<Contact> allContacts = [SELECT Id, Name FROM Contact];
    List<Interaction__c> allInteractions = [SELECT *fields* FROM Interaction__c];

    List<Interaction__c> relInterations = new List<Interaction__c>();for(Account act : accounts){
        for(Interaction__c relInt : allInteractions) {
            if((ID)relInt.AccountID__c = act.Id){