Problem: Feed Nibble Monster Till Full

Write a program that generates a number in [0, 500] at the beginning -- this corresponds to how hungry the monster is -- and keeps asking the user to feed the monster until that number falls to zero.

Each time the user feeds the monster a nibble, hunger decreases by the decimal value of the character (i.e. if the user feeds 'A' hunger decreases by 65). But when the user feeds the monster some character that isn't a nibble, the hunger increases by the decimal value of the character (since puking depletes energy).

Use while loop.

Sample runs:

Notice the loop exits after one iteration, because hunger was very low and one nibble made the monster full:

Notice hunger increasing after non-nibble (pink highlight):

Notice that the program just keeps going when the user feeds the monster only non-nibbles. Do you think the program will keep running forever if the user never gives the monster nibbles?