Count the letters of balloon with a dictionary.

The counts are {"b": 1, "a": 1, "l": 2, "o": 2, "n": 1}.

Both l and o appear twice. max returns the first one that it meets with the highest count, which is l.

So the answer is not the only possible one: o is as common as l. A tie is one more reason why a short text can fool the cracker.