Modify the program to output a coupon for a free haircut each time a client exceeds $1,000 in services. The coupon, which contains the client's name and an appropriate congratulatory message, is output during the execution of the update program when a client total surpasses $1,000. Make sure that only one coupon is printed per client, even if the client has purchased multiple services to pass the $1,000 cutoff value.