When adding and accessing elements to dictionaries, we might accidentally try to access a key that hasn’t been added to the dictionary yet. In that case, Python will tell us that a KeyError occurred and there isn’t such a key in the dictionary. To check if the key is in the dictionary, we can use the in keyword (exactly as we would do in lists, tuples, or sets).
You are asked to calculate the most frequent word in the essay and output it. You know that words are separated by a space and that you should ignore uppercase/lowercase difference. It is guaranteed that there is only a single most common word.
The input contains a single line of text, where words are separated by a space.
The output should contain the most frequent word of the input.