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

[EX Q]: Sentence: 'a man walking a large elephant down a dirt road'. Find frequency of the letter 'g'
[EX A]: 2

[EX Q]: Sentence: 'a group of people seated in chairs together and facing the same direction, with one man holding a soccer ball in his hands'. Find frequency of the letter 'm'
[EX A]: 2

[EX Q]: Sentence: 'a surfer in a black wet-suit rides a wave'. Find frequency of the letter 'f'
[EX A]:
1