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

[EX Q]: Sentence: 'a baby elephant walks beside an adult elephant along a post and cable'. Find frequency of the letter 'l'
[EX A]: 6

[EX Q]: Sentence: 'a woman walking on a shore next to a river'. Find frequency of the letter 'v'
[EX A]: 1

[EX Q]: Sentence: 'a plate of food with meat and broccoli on it'. Find frequency of the letter 'n'
[EX A]:
2