what does "keep the diffrence"here mean?
He told her that he had noted down exactly what he had borrowed so as to keep his accounts in order. As it happened this was true. He knew that his debts in Brasso amounted to exactly fifteen thousand, three hun- dred and seventy-seven crowns, and he would keep the difference as he would now have to find somebody who would pay back Dinora’s drafts and, until that person was found, he would need money to live. After all, he would never solve his problems if he didn’t go to balls and meet people ^ and no one could live without a cent in their pockets.