Why do I'm getting an error on inserting and updating the address in contact mailing address?

trigger ContactMailAddr on Contact (after insert, after update) 
{
    // first you create a list to store the Account ids
    List<Id> accountToSearch = new List<Id>();
    
    // get them from the contacts
    for (Contact contact : Trigger.new)
    {
        accountToSearch.add(contact.AccountId);
    }
    // query in the db
    List<Account> accounts = [SELECT Id, BillingStreet, BillingCity, BillingState, BillingCountry, BillingPostalCode FROM Account WHERE Id IN :accountToSearch];
    list<contact> contacts =new list<contact>([select id,AccountId,MailingCity,MailingState,MailingStreet,MailingCountry
                                               from contact where accountid in :accountToSearch]);
    // iterate over the accounts and contacts
    for (Account account : accounts)
    {
        for (Contact contact : Trigger.new)
        {
            // if a contact is set to the account then
            if (contact.AccountId == account.Id && contact.AccountId != null)
            {
                // copy the contact's address to the account's fields
                contact.MailingStreet = account.BillingStreet;
                contact.MailingCountry =  account.BillingCountry;
                contact.MailingState =  account.BillingState;
                contact.MailingCity =  account.BillingCity;
                contact.MailingPostalCode = account.BillingPostalCode;
                
            }
        }
    }
    // finally update the contacts records
    update contacts;
}

I'm getting an error on inserting and updating the address?