In 2017 axpayer T ("T") purchased a house for $900,000. T paid using $400,000 cash and took a mortgage (loan) of $500,000. T used the house exclusively as a vacation home. In 2022, when the house had a fair market value ("FMV") of $1,200,000, T sold the house to S subject to the $500,000 mortgage. T received $700,000 cash and S assumed the $500,000 mortgage. How much gain/income, if any, does I recognize in 2022?