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.

[Q]: A gropu of bulls are running down a street unattended.
[A]: gropu


[Q]: a bnuch of people stand around a brief case
[A]: bnuch


[Q]: A ma is riding a snowboard on a ski slope.
[A]:
ma