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

[Q]: Sentence: 'a woman throwing a frisbee on a field'. Find frequency of the letter 's'
[A]: 1


[Q]: Sentence: 'a stop sign next to houses with christmas lights'. Find frequency of the letter 's'
[A]: 7


[Q]: Sentence: 'crowds of people have lined a street to watch a parade'. Find frequency of the letter 'e'
[A]:
7