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 bah room with a toilet a sink and a bath tub
Example Output: bah

Example Input: Thee are two cows standing on a grass field
Example Output: Thee

Example Input: People standing at the bottom of a ski slope while others ski down in the sniw.
Example Output:
sniw.