trigger CreateOrUpdateContactsOnAccount on Account (after insert, after update) {
    Set<Id> accountIds = new Set<Id>();
    Map<Id, Integer> numContactsMap = new Map<Id, Integer>();
    
    for (Account acc : Trigger.new) {
        if (Trigger.oldMap.get(acc.Id).Location__c != acc.Location__c && acc.Location__c != null) {
            Integer numContacts = Integer.valueOf(acc.Location__c);
            accountIds.add(acc.Id);
            numContactsMap.put(acc.Id, numContacts);
        }
    }
    
    if (!accountIds.isEmpty()) {
        List<Contact> existingContacts = [SELECT Id, AccountId FROM Contact WHERE AccountId IN :accountIds];
        Map<Id, List<Contact>> contactsByAccountMap = new Map<Id, List<Contact>>();
        
        for (Contact con : existingContacts) {
            if (!contactsByAccountMap.containsKey(con.AccountId)) {
                contactsByAccountMap.put(con.AccountId, new List<Contact>());
            }
            contactsByAccountMap.get(con.AccountId).add(con);
        }
        
        List<Contact> contactsToInsert = new List<Contact>();
        List<Contact> contactsToDelete = new List<Contact>();
        
        for (Id accId : accountIds) {
            Integer numContacts = numContactsMap.get(accId);
            List<Contact> existingContactsForAccount = contactsByAccountMap.containsKey(accId) ? contactsByAccountMap.get(accId) : new List<Contact>();
            
            // Create new contacts if the number has increased
            for (Integer i = existingContactsForAccount.size() + 1; i <= numContacts; i++) {
                contactsToInsert.add(new Contact(
                    FirstName = 'New Contact',
                    LastName = 'Number ' + i,
                    AccountId = accId
                ));
            }
            
            // Delete existing contacts if the number has decreased
            for (Integer i = existingContactsForAccount.size() - 1; i >= numContacts; i--) {
                contactsToDelete.add(existingContactsForAccount.get(i));
            }
        }
        
        if (!contactsToInsert.isEmpty()) {
            insert contactsToInsert;
        }
        
        if (!contactsToDelete.isEmpty()) {
            delete contactsToDelete;
        }
    }
}

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