Custom deletion of contacts

I need to know how to delete contacts that dont have subscriptions either individual or in groups. I am using a custom class in the cms that implements IDeleteContacts

    public int Delete(int days, int batchSize)
    {
        var whereCondition = GetWhere();
        ContactInfoProvider.DeleteContactInfos(whereCondition, batchSize);


        return ContactInfo.Provider.Get().Where(whereCondition).Count();
    }

    /// <summary>
    /// Selects all contacts that do not have a 'ContactStateID' (are from outside the US).
    /// </summary>
    public string GetWhere()
    {
        var condition = new WhereCondition();
        condition.And(new WhereCondition().WhereEmpty("EverbridgeContactId").Or().WhereEmpty("SendGridContactId"));
        return condition.ToString(true);
    }



    Will this return the contacts that are in groups also because I dont want to delete a contact that is in a group and that group is added to a newsletter subscription

            public string GetWhere()
    {
        var condition = new WhereCondition();
        condition.And(new WhereCondition().WhereEmpty("CompanyContactId").Or().WhereEmpty("SendGridContactId"));

        ObjectQuery<SubscriberInfo> subscriberQuery = _subscriberInfoProvider.Get().TopN(1).Column("SubscriberEmail");
        condition.Or().WhereNotExists(subscriberQuery);

        return condition.ToString(true);
    }