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.

Ex Input:
A dek covered in both desktop computers and a laptop.

Ex Output:
dek


Ex Input:
a preson riding a horse on a dirt ground

Ex Output:
preson


Ex Input:
a man walks and talks on his cell phonr

Ex Output:

phonr