In this task, you need to count the number of times the given letter appears in the given sentence.

Input: Consider Input: Sentence: 'a little boy sitting on a bed in a bedroom'. Find frequency of the letter 'e'

Output: 3

Input: Consider Input: Sentence: 'a sheep in a field in front of other sheep'. Find frequency of the letter 'f'

Output: 3

Input: Consider Input: Sentence: 'a boy eating a donut on a string blind folded'. Find frequency of the letter 'b'
Output: 2