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

[Q]: Sentence: 'baseball player reaching back as he's about to throw the ball'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'a long row of tables displaying lots of fruit'. Find frequency of the letter 'o'
[A]: 5


[Q]: Sentence: 'a group of street signs on a pole next to a building'. Find frequency of the letter 'g'
[A]:
3