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

Sentence: 'one man grabbing another at a table while laughing'. Find frequency of the letter 'n'
5

Sentence: 'three people are gathered around sitting on a park bench'. Find frequency of the letter 'g'
2

Sentence: 'a person riding on top of a wave on a surfboard'. Find frequency of the letter 'a'

5