Irina cashes in Series I saving bonds during 2017. She receives $18755, of which $15000 was principal and the rest interest. Irina uses the proceeds to pay out-of-state tuition and fees totaling $16500 for her sr son, who is a full-time student during the year. She uses the rest of the proceeds to pay for her son's room and board. Irina's filing status is head of household. Irina's only other source of income is her $77050 salary. Compute Irina's exclusion for series EE and I interest and her AGI.