Billy is single and lives with his 70-year-old mother. Billy's mother is a resident in Canada, and she is wholly dependent on Billy for support due to her physical infirmity. Billy has incurred qualifying medical expenses of $3,200 for himself and $5,000 for his mother. In 2019 Billy has net income of $65,000 and his mother has net income of $12,000. There are no undeducted medical receipts from the prior year.

What is the maximum federal tax credit that Billy can claim for 2019 in relation to these medical expenses?