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:
teh people are walking next to a lake

Ex Output:
teh


Ex Input:
a vaat field full of weeds and dead grass

Ex Output:
vaat


Ex Input:
Two en flying through the air, while on water skis.

Ex Output:

en