Diane and Peter were divorced in 2018. The divorce agreement states that Peter is to have custody of their son, Stewart, and that Peter will be entitled to the dependency exemption. In addition, Diane is required to pay Peter $12,000 per year until Stewart turns 18 years of age, when the yearly amount will be reduced to $8,000. What is Diane’s allowable deduction, and how should it be deducted on her return?