Jerry took out a fully amortizing, $3/1$ hybrid, adjustable rate mortgage $($ARM$)$ of $$1,200,000$ with $28-$year maturity.

The interest rate is indexed to SOFR and the margin for Jerry was $3\%.$

At the time of the loan origination, SOFR was $3\%.$

The lender offers a teaser rate of $1\%$ during the first $3$ years. The accrual, however, rate is still based on the SOFR and the $3\%$ margin.

At the end of the $3$rd year, the SOFR was $5\%.$

In the $40$th month, Bronn$$s monthly payment equals $