The given sentence contains a typo which could be one of the following four types: (1) swapped letters of a word e.g. 'niec' is a typo of the word 'nice'. (2) missing letter in a word e.g. 'nic' is a typo of the word 'nice'. (3) extra letter in a word e.g. 'nicce' is a typo of the word 'nice'. (4) replaced letter in a word e.g 'nicr' is a typo of the word 'nice'. You need to identify the typo in the given sentence. To do this, answer with the word containing the typo.

Example Input: Crodw of people standing around while someone flies a kite
Example Output: Crodw

Example Input: Sevrral items of different designed luggage next to a wall.
Example Output: Sevrral

Example Input: Two opposing players are running down the field for a ball.
Example Output:
None