At the end of 2016, Framber Company received $8,000 as a prepayment for renting a building to a tenant during 2017. The company erroneously recorded the transaction by debiting Cash and crediting Rent Revenue in 2016 instead of 2017.

I know that i'm debiting rent revenue and credting retained earnings to offset what was done in 2016 but i'm not sure how to figure out the amount I use.