During $2023,$ Cathy takes five key clients to dinner and incurs the following costs: $$320$ limousine rental and $$1120$ for dinner; assume that there were substantive business discussions during dinner. Several days after the function, Cathy mails each client a pen costing $$25.$ In addition, Cathy pays $$4$ for gift wrapping and mailing each pen. Assuming adequate substantiation and a business justification, what is Cathy's deduction?