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

[EX Q]: Sentence: 'a large bathroom with marble floor, counter, and bath'. Find frequency of the letter 'f'
[EX A]: 1

[EX Q]: Sentence: 'a girl that has a kite in the air'. Find frequency of the letter 'r'
[EX A]: 2

[EX Q]: Sentence: 'a woman holding a kid is walking down the street with an umbrella'. Find frequency of the letter 'g'
[EX A]:
2