You have to develop an Automated Teller Machine (ATM) allowing cash withdrawals.

The ATM main features:

• it allows cash withdrawals with the following denominations: 5 €, 10 €, 20 €, 50 €
• it keeps track of the currently available amount of banknotes on the different denominations (e.g. how many 20 € notes are still available in the ATM)
• it raises an error condition if the notes are not enough to complete the requested cash withdrawal
• it gives priority to the higher value denominations first before using the smaller denominations
• it can be configured to support different denomination sizes and currencies (e.g. 5 $, 10 $, 20 $, 50 $, 100 $)

(taken from https://www.youtube.com/watch?v=fkhm5kOUeJU)

Credits to Piergiuliano Bossi for the original kata.