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

[EX Q]: Sentence: 'a woman walking on a shore next to a river'. Find frequency of the letter 'v'
[EX A]: 1

[EX Q]: Sentence: 'an elephant with broken tusks stands in front of a hill and boulders'. Find frequency of the letter 'n'
[EX A]: 7

[EX Q]: Sentence: 'a small brown tiled bathroom in a house'. Find frequency of the letter 'e'
[EX A]:
2