TASK DEFINITION: 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.
PROBLEM: Thre zebra walk in an enclosure next to a wall.

SOLUTION: Thre

PROBLEM: A laoptop and bowl of food sits on top of the food.

SOLUTION: laoptop

PROBLEM: Two rall birds are standing in some mulch.

SOLUTION:
rall