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: A griup of people standing on top of a sandy beach.

SOLUTION: griup

PROBLEM: Some people are playing frisbee in a vallye.

SOLUTION: vallye.

PROBLEM: Two srufers hold their boards in their arms while walking on the beach.

SOLUTION:
srufers