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

[Q]: Sentence: 'a snow filled mountain with a guy with ski's'. Find frequency of the letter 'f'
[A]: 1


[Q]: Sentence: 'a person holding a wine glass in one hand and bread sticks in the other'. Find frequency of the letter 'd'
[A]: 4


[Q]: Sentence: 'a man is jumping off the street on a skate board'. Find frequency of the letter 'i'
[A]:
2