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: A yong child holds an umbrella while an adult pulls the sleigh.
Example Output: yong

Example Input: A coulpe of buses driving down a street next to tall buildings.
Example Output: coulpe

Example Input: Dimly lir room with a lap top computer on a wooden desk with headphones, cell phone and assorted paper and books.
Example Output:
lir