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

[EX Q]: Sentence: 'two men with colorful ties are posing for a picture'. Find frequency of the letter 'r'
[EX A]: 4

[EX Q]: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'
[EX A]: 2

[EX Q]: Sentence: 'there are black and white poles along a street corner'. Find frequency of the letter 'e'
[EX A]:
8