A house with two bedrooms and one living room is priced at 248,300 yuan. The first payment is 63,500 yuan, and the monthly payment is 770 yuan. How many years later will it be paid off?
一套两室一厅的住房，售价248300元，首次付款63500元，以后每月付770元，那么多少年后能付清？
<gadget id="calculator">248_300 - 63_500</gadget>
<output>184_800</output>

<gadget id="calculator">184_800 / 770 / 12</gadget>
<output>20</output>

<result>20</result>