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

[Q]: Sentence: 'a man with a large grey and black beard and glasses and a tie'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'silhouette of person playing frisbee with moutain and sunset'. Find frequency of the letter 'i'
[A]: 5


[Q]: Sentence: 'baseball ball pitcher getting ready to throw the ball'. Find frequency of the letter 'b'
[A]:
4