instruction:
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.
question:
a resd white and black sign against a white background
answer:
resd


question:
A trqain rolling by a mountain stream and trees.
answer:
trqain


question:
A small herd of zebras on the plaibs.
answer:

plaibs.