need help with sdjusting entry

Blake Company was hired on November 1, 2021 to clear snow in the parking lots at Cape Breton University. The going rate was $2,500 per month. The amount was guaranteed regardless of how much snow fell. The contract was to run from November 1, 2021 to March 31, 2022. Cape Breton University paid Blake Company in full $12,500 on November 1,2021. If we were preparing adjusting entries for Blake Company annually on December 31 , what would be the adjusting entry