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 man standing on a tennis court holding a racquet'. Find frequency of the letter 's'
[A]: 2


[Q]: Sentence: 'an aerial photo of some buildings and highway'. Find frequency of the letter 'b'
[A]:
1