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

[Q]: Sentence: 'a street scene looking at the back of the stop sign'. Find frequency of the letter 't'
[A]: 6

[Q]: Sentence: 'a woman holds some baked goods at the convention'. Find frequency of the letter 'd'
[A]: 3

[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