Leetcode 2241. Design an ATM Machine

Design an ATM with five fixed denominations (20, 50, 100, 200, 500) that supports depositing counts of each bill and withdrawing a given amount. For withdraw, greedily take as many of the largest available bills as possible (500→20) and return the counts used or [-1] (and make no change) if that greedy process cannot produce the exact amount.