Imagine you have a number set and, some of these numbers create a given target number when they summed. In real world problem, we have a group of people who has to pay different amounts of fees to the bank. These fees are comma seperated and generally unique. The bank tells us that some people didn't pay and the total unpaid amount; but it does not mention how many people and who did not pay. We know unique amounts that people should pay. This app helps to find out which unique amounts (puzzle pieces) created the total number(completed puzzle.)