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

[Q]: Sentence: 'a teddy bear is sitting on a heart shaped patio chair outside'. Find frequency of the letter 'i'
[A]: 6

[Q]: Sentence: 'a gray colored pigeon that is perched on a railing outside of a building, with other buildings in the background'. Find frequency of the letter 'e'
[A]: 7

[Q]: Sentence: 'a very tasty looking pasta dish with some greens'. Find frequency of the letter 'a'
[A]:
4