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

[EX Q]: Sentence: 'an image of a street sign with a corner restaurant'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a woman fully dressed as a geisha'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'a person is coming down a hill in the snow on skis'. Find frequency of the letter 'c'
[EX A]:
1