Given the task definition, example input & output, solve the new input case.
In this task, you need to count the number of times the given letter appears in the given sentence.
Example: Sentence: 'a large group of bananas proped up on several bicycles'. Find frequency of the letter 'e'
Output: 5
The letter 'e' appears 5 times in the sentence.

New input case for you: Sentence: 'this marketplace has a lot of fresh fruit and vegetables'. Find frequency of the letter 'v'
Output:
1