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

Sentence: 'a blue fire hydrant painted on the bottom of it'. Find frequency of the letter 'h'
2

Sentence: 'a small dog sits in the rear window of a car'. Find frequency of the letter 'm'
1

Sentence: 'a man and woman in street next to a bench'. Find frequency of the letter 'a'

5