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

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


[Q]: Sentence: 'man is snow gear and skis skiing in the snow'. Find frequency of the letter 'i'
[A]: 5


[Q]: Sentence: 'male baseball player dressed in red stands on the infield'. Find frequency of the letter 'e'
[A]:
8