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

[Q]: Sentence: 'a line of people on motorcycles on the road'. Find frequency of the letter 'e'
[A]: 5

[Q]: Sentence: 'a river with a long dragon boat in it and rowers on the boat in sets of two, along with two other people'. Find frequency of the letter 'h'
[A]: 4

[Q]: Sentence: 'a very hair arm holds a blade next to an open medicine cabinet'. Find frequency of the letter 'l'
[A]:
2