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

[EX Q]: Sentence: 'a train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'
[EX A]: 3

[EX Q]: Sentence: 'a picture of a toilet and toilet paper in a bathroom'. Find frequency of the letter 'o'
[EX A]: 5

[EX Q]: Sentence: 'a close up on a cows head in a pen'. Find frequency of the letter 'n'
[EX A]:
3