Calculate the number 2878

Little Johnny wanted $100 for a new bike and prayed for two weeks, but nothing happened.Then he decided to write God a letter asking for the money. When the local postmaster saw the letter addressed to “God, USA,” he decided to send it to the President of the United States.The President was so impressed, touched, and amused that he instructed his secretary to send the little boy a $5 bill.Little Johnny was delighted with the $5 and wrote a thank-you note to God. It read: “Dear God, thank you for sending the money. However, I noticed that for some reason you had to send it through Washington, D.C. As usual, those crooks deducted $95.”