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: The man on a red bike is looking baxck.

SOLUTION: baxck.

PROBLEM: a mab holds a box of doughnuts as he smiles

SOLUTION: mab

PROBLEM: A trqain blowing out lots of steam and smoke.

SOLUTION:
trqain