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

[EX Q]: Sentence: 'two people in a snowy place near a wooden fence'. Find frequency of the letter 'n'
[EX A]: 5

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

[EX Q]: Sentence: 'man inserting a sausage in to a sandwich at a sidewalk bbq'. Find frequency of the letter 'h'
[EX A]:
1