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

Input: Consider Input: Sentence: 'the wooden kitchen has a small child's plastic table in it'. Find frequency of the letter 'n'

Output: 3

Input: Consider Input: Sentence: 'a stop sign near a rail road crossing sign'. Find frequency of the letter 'g'

Output: 3

Input: Consider Input: Sentence: 'a woman holding an umbrella walks along a city sidewalk'. Find frequency of the letter 'w'
Output: 3