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

[EX Q]: Sentence: 'a woman is looking at sheep off in a field'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'
[EX A]: 3

[EX Q]: Sentence: 'a airplane sitting on a runway at a small airport'. Find frequency of the letter 'n'
[EX A]:
4