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

[EX Q]: Sentence: 'some sheep are standing in a grassy field'. Find frequency of the letter 'n'
[EX A]: 3

[EX Q]: Sentence: 'three elephants walk up a dirt trail from the water'. Find frequency of the letter 'l'
[EX A]: 3

[EX Q]: Sentence: 'a young tyke swings at the ball which is mid air, not far from his baseball bat'. Find frequency of the letter 'e'
[EX A]:
3