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

[EX Q]: Sentence: 'a jet flying through the clear blue sky'. Find frequency of the letter 'g'
[EX A]: 2

[EX Q]: Sentence: 'a batter, catcher and umpire waiting for the pitch and a major league baseball game'. Find frequency of the letter 'c'
[EX A]: 3

[EX Q]: Sentence: 'in the background, a shaded blue mountain and soft blue sky, fronted by a boat on water, leads to a foregrounds of water spry and a big wave, bearing a man in a rolled up top and trunks, hunched over and riding a surf board'. Find frequency of the letter 'r'
[EX A]:
14