To solve this question we have to make deduct these 2 years. 2120 minus 1977 will give the answer.
You are 143 years old.
(1716 months are passed.)
From 1977 to 2120 there are 143 years. If you want to learn your age in 2120 (born in 1977) your age is 143.
Let's see what will be your age if you born +1 or -1 from that date.