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

[EX Q]: Sentence: 'a giraffe sticking it's tongue out near a window'. Find frequency of the letter 'a'
[EX A]: 4

[EX Q]: Sentence: 'a man and a woman are walking down the street with an umbrella over their heads'. Find frequency of the letter 'w'
[EX A]: 4

[EX Q]: Sentence: 'soccer players on opposite teams fight for control over a ball'. Find frequency of the letter 't'
[EX A]:
4