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

[Q]: Sentence: 'man in red shirt with black suitcase standing outside of building'. Find frequency of the letter 'i'
[A]: 8

[Q]: Sentence: 'a black horse with a white dot on its forehead'. Find frequency of the letter 't'
[A]: 4

[Q]: Sentence: 'an old man in a funny hat eating'. Find frequency of the letter 't'
[A]:
2